Boom with mast assembly

ABSTRACT

A torsion- and bending resistant boom formed of beams running the length of the structure, a set of pierced, transverse flanges arrayed along, and substantially perpendicular to, the length of the structure, a continuous longitudinal member running the length of the structure, piercing the flanges, and several further longitudinal members, outward of the first member. The longitudinal members are welded to the flanges. An elevatable mast assembly raises and lowers the boom, and has a mast and guides formed of hollow tubes, and rollers between the guides and the mast, the rollers transferring torque loading to the guides.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to booms and mast structures forsupporting a load, and to those supporting torque-inducing loads. Inparticular, if relates to a boom structure that may be rotated, and amast structure that may be elevated. More particularly, it relates to aboom and mast structure mounted on a mobile platform for deployment of asystem for inspection of vehicles or containers.

A boom used to support a load at a distance from a vertical support mustresist deformation resulting from the downward forces applied thereto bythat load, and the torque created thereby. In addition, where that boomand load may be subject to acceleration resulting from translation orrotation, or other application of forces, in other than the verticaldirection, the boom must also resist torsion along its long axis. Thenecessity of resisting torsion will be increased by a further load inthe form of a vertical portion extending downwardly from its far end,which acts to intensify torsional effects created by movement out of thevertical.

A mobile transport may have a mast mounted thereon, and a boom mountedatop the mast, which is rotatable with respect to the mast, and whichhas a vertical portion supported by its far end. For use in inspectionof vehicles or containers, the mobile transport may mount a transmitterand sensors, on the boom and the vertical portion, for inspectingvehicles or containers which pass below and inward of the boom as themobile transport is propelled past those items. In this situation, inorder to increase the accuracy of the inspection, it is particularlyimportant to resist torsion and bending to minimize changes in theposition of the boom relative to the transport. Further, where the mastis to be raised of lowered along a vertical axis, the system used to doso must also guide that movement, and resist torque created by the loadof the boom and its load.

2. Background Art

A structure supporting a load at a distance is subject to both bendingand torsional effects, particularly when a further perpendicularstructure is supported at a distance from the point of support. The useof metal tubes or beams for constructing such structures is known, as isuse of C-channel beams to resist torsion or bending. However, suchstructures, if relatively long, are subject to buckling if notreinforced, and may not be sufficient to resist higher bending andtorsion loads. Construction, and reinforcement of, such a structureinstalled upon a mobile platform must also address weight concernsrelated to vehicle weight and stability. Further, such structures mustalso resist movement of the structure relative to the point of support.Previous devices disclosed in patents include the following:

U.S. Pat. No. 5,152,659 to Waka discloses a boom assembly having aninflection point therein that utilizes two opposing upper and lowerwelded C-channels to form a box structure. The booms are used to formthe arms supporting the bucket of a bulldozer. Waka does not address theuse of tubes, or other reinforcements.

U.S. Pat. No. 5,568,829 to Crawford et al. discloses a boom for asliding boom delimber, for use in the logging industry, the boomutilizing a pre-stressed I-beam to enclose and support power and controlcables to the delimbing apparatus attached at its end. Crawford et al.do not address the use of tubes, or other reinforcements.

U.S. Pat. No. 5,692,028 to Geus et al. discloses a x-ray examiningapparatus mounted on a mobile vehicle, including a support structure anddetectors mounted on the supporting structure. Geus et al. do notaddress construction of any boom, mast or other structure supporting thedetectors, or how to minimize movement of the support structure relativeto the vehicle.

U.S. Pat. Nos. 5,764,683 and 5,903,623 to Swift et al. disclose a mobiledevice for inspection of containers, including detectors that may besupported from a horizontal boom extending from the mobile device. Swiftet al. do not address construction of a boom or mast supporting thedetectors, or how to minimize movement of the boom relative to themobile device.

In addition, a mast assembly is known for raising and lowering a loadfrom a mobile platform; such structures often utilize a mast formed of ahydraulic piston. A lateral load, such as that resulting from torqueapplied by a boom in the present invention, may be applied. In theabsence of a separate guiding system, lateral loading would betransmitted through the hydraulic seals (often O-rings) to the cylinderwalls, which may unduly compress those seals, and cause failure of theseseals. Because a hydraulic lift system can fail, permitting the mast todrop, such systems may include a latching mechanism, to support the mastand load in an elevated position. However, this adds weight and cost.Such structures do not address the torque and load concerns of thedescribed inspection system.

It can be seen that the foregoing do not meet all of the needs for aboom and mast structure that is rigid and torsion-resistant, andresistant to buckling and undesirable movement.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a highly rigid, torsion-resistant, andbuckle-resistant boom design, which may include a vertical portion,providing stable support for the supported load. This invention providesa horizontal boom section, and in a preferred embodiment includes avertical boom section depending downwardly from the distal end of thehorizontal boom section. In another preferred embodiment, the proximalend of the horizontal boom section is preferably mounted to a verticalsupport, such as an elevatable mast, permitting vertical movement of theboom/mast structure, and rotation of the boom structure.

In preferred mode of operation, a series of vehicles, typicallytractor-trailer rigs, or cargo containers, are placed in a line parallelto the intended direction of travel of the mobile inspection unit whichincorporates a preferred embodiment of the invention. The unit ispropelled forward so that a scanning zone of an inspection system passesthrough each of the rigs or containers in succession. The data gainedfrom these scans is viewed and interpreted by an operator in the mobiletransport. Accurate alignment and minimized relative movement betweenthe radiation source and the sensors is critical. Because the sensorsare mounted upon the boom sections, it is important to increase thetorsional and bending resistance, and the resistance to buckling, ofthose sections, particularly the horizontal boom section. Torsion forcesmay act upon the boom in a number of ways. For instance, forwardacceleration of the mobile inspection unit, and the resistance to motionof the boom structure, will result in inertia opposing thatacceleration. This effect will be increased where that resistance isplaced at a distance from the source of support, such as the verticalboom structure, supported at the end of the horizontal boom structure.Other sources of torsional effects include wind resistance andaccidental obstruction of the boom structure. Similarly, bending forcesare present resulting from the weight of the sensors and the boom's ownweight.

In a preferred embodiment, a horizontal boom section includes acontinuous inner tube, or rod, which runs the length of the horizontalboom section. This inner tube penetrates several flanges arrayed alongthe length of the boom section. The flanges are preferably perpendicularto the inner tube, and are joined to it at the penetration. Individual,discontinuous, outer tube segments are placed outwardly of the innertube, preferably concentrically, between and abutting, but notpenetrating, the flanges. The outer tube segments are joined at theirends to the flanges' faces, preferably in grooves sized to thosesegments. Inward-facing C-channel beams, running the length of thehorizontal boom section, are joined on their inward faces to theflanges' side edges, preferably congruently. Tensioning cables provideupward support for the ends of the structure, and permit a torque to beapplied to straighten the structure.

Preferably, the boom further includes a vertical boom section, includinga set of continuous tubes, or rods, which run the height of the verticalboom section, and penetrate several flanges arrayed along its height.The several flanges are substantially perpendicular to the vertical, andpreferably congruent to inward-facing C-channel sections. The C-channelsections run the height of the vertical boom section, and are joined tothe flanges. In a particularly preferred embodiment, a joint is providedroughly in the middle of the vertical boom section, permitting the lowersegment to be folded upwardly against the upper segment, reducing theoverall length of the vertical boom section for ease of stowage.

In a preferred embodiment, in order to facilitate elevation and rotationof the boom relative to a mobile transport, a mast-head and mastassembly are provided. The horizontal boom section, to which thevertical boom section is preferably mounted, is mounted to a mast-head,which is itself mounted to a mast assembly. The mast assembly is mountedto the chassis of the mobile transport. A mast assembly includes a mastguide and an elevation system to elevate the mast and the boom structuresupported thereby. The mast-head is mounted to the top of the mastassembly, facilitating joinder of the horizontal boom section to themast. The mast-head includes a rotation drive for rotating the boomstructure. A counterweight structure may also be mounted to themast-head, opposing the torque created by the weight of the boomstructure.

The mast is preferably rigid, resistant to torque, and transmitsout-of-vertical forces to the chassis without adversely affectingoperation of the elevation system. In a preferred embodiment, acomposite mast, formed of a two-by-two square grouping of hollowsquare-section tubes provides such rigidity and strength. The mastassembly further preferably includes a guide for the mast, whichincludes four similar hollow square-section tubes fixed to the chassisoutwardly of the corners of the mast, and rollers between the mastcorners and the inner corners of the guide. Preferably, several sets ofrollers are positioned at varying heights along the mast. The rollerspermit translation of the mast relative to the guide, which is fixed tothe chassis, but transmit to that chassis the forces out of thevertical, created by torque of the weight of a boom or load. Theelevation system also preferably includes a screw and a screw jack,which require little power for operation and are very reliable. Thissystem has advantages over alternatives, such as a hydraulic lift for asimilar mast, or a mast formed of a hydraulic piston. The weight andcost of an additional latching system are avoided by using the screwjack system, which does not depend upon a hydraulic power source forlift, and can maintain position without power input. The presentinvention also avoids compression and failure of hydraulic seals byomitting them and transmitting any lateral loads via rollers, which aredesigned to transmit this load to the guide.

In a further preferred embodiment, loads supported by the boom sectionsinclude their own weight and sensors for detecting transmitted radiationfor inspecting vehicles and containers inward of and below the boom.Various types of sensors may be used, such as transmission, backscatter,sidescatter and forward scatter detectors. In this preferred embodiment,the boom structure is mounted on a mast, itself mounted to the chassisof a mobile transport. The boom sections may be rotated relative to themast, to a position in which they extend roughly perpendicular to thetransport's direction of forward travel. The bottom end of the verticalboom section preferably extends proximate the ground surface. In thisposition, the horizontal and vertical boom sections form, with theadjacent side of the transport, an essentially planar rectangularscanning zone. A radiation source, typically an X-ray emitter, ismounted on the mobile transport, along with the necessary supportequipment, power source and operator. The X-ray device emits penetratingradiation into the scanning zone and toward sensors mounted upon theinward face of the vertical boom section, and upon the lower face of thehorizontal boom section. The X-ray device may provide coverage of thescanning zone by repeatedly sweeping a narrowly focussed beam aligned tothe plane, or by other techniques permitting radiation transmissioncovering a planar area. If the radiation would tend to penetrate thesensor, or the boom's structural material, additional absorptivematerial, such as lead, may be employed to do so.

The further scope of the invention will become apparent upon the reviewof the detailed description of the preferred embodiments. It shouldhowever be understood that these descriptions do not limit the scope ofthe invention and are given as examples only, and that various changesand modifications which are fully within the scope of the presentinvention will become apparent to those skilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is more easily understood with reference to thedrawings, in which:

FIG. 1A is a partial cutaway top view of the mobile inspection unitdepicting the boom assembly in the deployed position.

FIG. 1B is a partial cutaway elevation of the mobile inspection unitdepicting the boom assembly in the deployed position.

FIG. 1C depicts partial section A—A of the mobile inspection unit.

FIG. 1D is an end view of the mobile inspection unit depicting detail ofthe boom assembly in the deployed position.

FIG. 2A is a top view of the mobile inspection unit depicting the boomassembly in the stowed position.

FIG. 2B is a partial cutaway elevation of the mobile inspection unitdepicting the boom assembly in the stowed position.

FIG. 3 depicts section B—B of the vertical boom section.

FIG. 4 depicts section C—C of the horizontal boom section.

FIG. 5A is an elevation of a horizontal boom section flange.

FIG. 5B is an edge view of a horizontal boom section flange.

FIG. 6A depicts section D—D of the instrument boom.

FIG. 6B depicts partial section E—E of the horizontal boom section.

FIG. 6C is a partial cutaway elevation of the mast-head.

FIG. 6D depicts section F—F of the mast-head.

FIG. 7A is a top view of a vertical boom section flange.

FIG. 7B is an edge view of a vertical boom section flange.

FIG. 8A is an elevation of the joint between horizontal and verticalboom sections.

FIG. 8B is an end view of the joint between horizontal and vertical boomsections.

FIG. 9 depicts section G—G of the vertical boom section.

FIG. 10 is a partial cutaway of detail of the mast assembly and rotationsystem.

FIG. 11 is a partial cutaway top view of the rotation system.

FIG. 12 depicts section H—H of the mast assembly.

FIG. 13A is a front view of a terminal flange.

FIG. 13B is a side view of the terminal flange of FIG. 13A.

FIG. 14A is a plan view of the mast-head extension, with the cover panelremoved, showing joinder to the mast-head.

FIG. 14B is an elevation of the mast-head extension with the sheetingremoved, showing joinder to the mast-head.

FIG. 15 depicts detail of the wire cage transmission.

FIG. 16 depicts detail of section I—I.

FIG. 17A is an elevation of an alternative horizontal boom sectionflange.

FIG. 17B is an edge view of an alternative horizontal boom sectionflange.

FIG. 17C is a partial cutaway bottom view of alternative horizontal boomsection.

FIG. 18 is an exploded view of the joint between horizontal and verticalboom sections.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the accompanying figures, and in particular to FIGS.1A-1D, a specific preferred embodiment of the present invention isdepicted as mobile inspection unit 1 including instrument boom 10.Instrument boom 10 includes horizontal boom section 20, vertical boomsection 22; sensor packages 24, and associated mast assembly 12. Mastassembly 12, mounted on chassis 6 of mobile transport 2, includes mast13, mast-head 14, mast guide 15, counter-weight 16 and turntable bearing17.

Referring also to FIG. 2B, mobile inspection unit 1 may beself-propelled and operated from cab 4, or may incorporate anindependent tractor (not depicted). Inspection unit 1 moves alongmovement axis 5 (FIG. 1A), normally also the longitudinal axis of theunit. Mobile inspection unit 1 includes mobile transport 2, which willordinarily have a conventional main drive system 3, suitable forpropelling mobile inspection unit 1 on ordinary roads or highwaysystems. Drive system 3 may include such conventional components as adiesel engine, transmission, drive shaft, suspension components, axles,brakes and a steering system for steering the front set of wheels 7.Mobile transport 2 further includes chassis 6, and transport body 8.Transport body 8 is mounted on chassis 6 in a conventional fashion,while chassis 6 is supported by wheels 7. The number and arrangement ofwheels may vary with the load to be borne, the desired chassis size andthe use of an independent tractor.

Referring to FIG. 1A, transport body 8 comprises forward compartment106, and operator compartment 107, preferably separated by wall 109.Forward compartment 106 includes cathode unit 104 and anode unit 105,which are operably connected to radiation emitter 112 in a manner knownto persons skilled in the art. Emitter 112 is capable of emittingpenetrating radiation suitable for inspection of vehicles and containersfor contraband such as illegal drugs, weapons and the like. Emitter 112,in the preferred embodiment is an X-ray emitter; any of several types ofemitters may be employed depending upon target composition and otherdesign criteria. Oil cooler 108 is preferably included, and providescooling for cathode and anode units 104, 105; its capacity may bedetermined by a person of ordinary skill based upon the cooling needs ofthe specific equipment utilized. Referring to FIGS. 1A, 1B, power issupplied by generator 102, preferably capable of providing 100 kWthree-phase power, mounted upon the rear portion of chassis 6. A modelDCA-100 by M.Q. Power is acceptable. Cooling for transport body 8 isprovided by air conditioning units 9, preferably three-ton models,mounted upon transport body 8.

Referring to FIGS. 1B and 1C, equipment compartment 103 is adjacentforward compartment 106, and the exterior of transport body 8, andhouses emitter 112, beam collimator 113 and backscatter detectors 116.Preferably, in order to mount emitter 112 close to ground 125 to permitinspection of low portions of target 131, subfloor 111 is used,supporting emitter 112 and collimator 113. Subfloor 111 is preferablymounted as low as 12 inches above ground 125. Emitter 112 should bemounted in such a manner as to reduce movement relative to instrumentboom 10, and preferably in a rigid fashion, directly or indirectly, tochassis 6. In operation, protective doors 117 are opened to expose thisequipment to inspection target 131. Protective doors 117 may also beclosed, as in FIG. 2B, during transport or otherwise to protect theequipment.

In FIGS. 1A-1C, emitter 112, operating with cathode and anode units 104,105, emits penetrating radiation aligned with the deployed position ofinstrument boom 10. This penetrating radiation preferably passes throughcollimator 113, which narrows this beam in a fore and aft direction andrestricts it to a roughly planar scanning zone 114, which is directedtoward sensors 24. Sensors 24 are suitable for detecting penetratingradiation emitted by emitter 112. Scanning zone extends from an anglea1, preferably below horizontal, to angle a2, above horizontal.Preferably, scanning zone 114 extends from about 4 degrees below thehorizontal to about 74 degrees above. These values may differ dependingupon the size of target 131 and its placement relative to emitter 112,and may be determined by a person of skill in the art.

Turning to FIGS. 1B, 1C, 10 and 12, mast guide 15, a portion of mastassembly 12, is also located within forward compartment 106. Mast guide15 encloses and supports mast 13, and the mast elevation system. Mastguide 15 is mounted, preferably by welding, to mast assembly base 21.Base 21 is mounted to mobile transport 2, preferably to chassis 6,providing support for instrument boom 10. Mast 13, supported by guide15, acts as a vertical support of the end of horizontal boom section 20.In different embodiments, an end support, which may provide one or bothof vertical support or torque for horizontal and vertical boom sections20, 22, may also be provided directly by a mast-head structure, the mastitself, or another supporting structure, known to a person of ordinaryskill in the art.

Referring to FIGS. 1C, 10 and 12, the mast elevation system preferablyincludes screw jack 91, hub nut assembly 92 and screw 93. Screw jack 91includes an electric motor and a jack, and is mounted to assembly base21. A ½ to 1 H.P. motor, and a ten-ton load capacity jack, fortransferring the input of the motor to screw 93 were found acceptable.In a preferred embodiment, an ACTIONJAC brand model no. 10BSJ jack isused in screw jack 91. Screw jack 91 rotates screw 93, which acts uponhub nut assembly 92 to elevate mast 13 within mast guide 15. Hub nutassembly 92, within which screw 93 rotates, translates screw 93'srotation to motion along a vertical axis aligned with screw 93 and hubnut assembly 92; preferably this vertical axis is aligned with mast 13'svertical axis. Hub nut assembly 92 incorporates multiple sets of ballbearings transferring the load of mast 13 to screw 93, and isadvantageous over other options, such as a simple hub threaded to screw93, by offering lower resistance to operation, needing less lubrication,and having a lower power requirement for the motor for screw jack 91.Hub nut assembly 92, fixed to mast 13 via mast baseplate 174, transmitsthe vertical motion to mast 13, while screw 93 is fixed to mastelevation drive 91. Screw cutaway 95, formed by removing interiorportions of mast tubes 176, permits rotational and translationalmovement of screw 93 relative to mast 13. Screw guard 87, preferablyfixed within screw cutaway 95, prevents other components, e.g. cabling,from contacting screw 93, and either damaging that component or foulingscrew 93.

In another embodiment, the mast elevation system comprises a hydraulicpiston assembly fixed to mast 13, including a hydraulic pump, a pistonacting upon mast 13, preferably upon baseplate 174, controls and,preferably, a latching mechanism. The latching mechanism is used tomaintain elevation of mast 13 should the hydraulic system lose pressureor otherwise fail. Failure, and uncontrolled dropping of mast elevation,during operations, could result in horizontal boom section 20 contactingtarget 131 and significant damage to both. In this way the above screwjack system is advantageous, in that such a latching mechanism isunnecessary.

Remaining with FIGS. 1C, 10 and 12, operation of the mast elevationsystem raises instrument boom 10, about 22 inches in a particularlypreferred embodiment, to create top clearance 129 between target 131 andsensor package 24 on horizontal boom section 20, when instrument boom 10is in the deployed position. In the preferred embodiment, top clearance129 is between about six and about eight inches, and this results insensor package 24 being about 168-169 inches above ground 125 wheninstrument boom 10 is in fully raised position, as depicted in FIG. 1C.Ground clearance 126 between lower boom segment distal end 29 a ispreferably about five inches in the deployed position. In the raisedposition of this preferred embodiment, the top of instrument boom 10 isabout 184 inches above ground 125, and the bottom of sensor package 24on horizontal boom section 20 is about 168 inches above ground 125.Turning to FIG. 2B, in this preferred embodiment's lowered position, theunderside of mast-head 14 clears the top of transport body 8 by about 6inches, while sensor package 24 is about 146 inches above ground 125,and when in the stowed position, stowed clearance 132 is about fourinches above the top of transport body 8, and the top of boom 10 is nomore than 162 inches above ground 125. Returning to FIG. 1C,horizontally, there is preferably at least about 144 inches betweenprotective doors 116, on the working side of transport body 8, andsensor package 24 on vertical boom section 22, which permits sideclearance 128 of about 21 inches on either side of a target 131 having aroad-legal width of 102 inches.

Remaining with FIGS. 1C, 10 and 12, mast 13 comprises a plurality ofmast sections and guide rails 179. In a preferred embodiment, the mastsections are four mast tubes 176, and in a particularly preferredembodiment, mast tubes 176 are hollow, squared tubes, about six inchessquare in section, having a wall thickness of about ⅜ inch, and areabout 96 inches in height. Mast tubes 176 are preferably constructed ofstainless steel or another steel suitable for the predicted loading.Preferably, four mast tubes 176 are arranged in a parallel fashion in asquare two-by-two array, and are mounted together by weldingintermittently along the exposed seams/edges between the tubes. Mastbaseplate 174 is also fixed, preferably by welding, to the lower ends ofmast tubes 176, which assists the tubes to retain their configuration.Mast top plate 164 is similarly fixed to the upper ends of tubes 176.Mast 13 is aligned on a translation axis, preferably vertical, as ismast guide 15, to permit vertical translation. Mast tubes 176 aremounted at their upper end, via mast top plate 164, to lower plate 158of turntable 17, in FIG. 16, preferably by welding. Preferably, fourguide rails 179 are mounted to the outer corners of the square array ofmast tubes 176, by fixing the inner face of the rail to the exposedouter corner of each of mast tubes 176. In one embodiment, guide rails179 comprise ⅜ thickness, four inch width angle pieces, about 88 inchesin height, preferably made of stainless steel or other suitable steelmaterials. Other designs for an elevatable mast are known to persons ofskill in the art.

Remaining with FIGS. 10 and 12, mast guide 15 comprises guide tubes 178,one or more sets of roller assemblies 177 and additional guide rails179. Guide tubes 178 are joined at their bases to mast assembly base 21,preferentially by welding. Guide tubes 178 are preferentially arrangedoutwardly from the exposed outer corners of mast 13, radially andsymmetrically from the center of mast 13, preferably such that fourguide tubes 178 are outward of the corners in both the forward/aft andside-to-side directions, and are positioned parallel to each of masttubes 176. In one embodiment, guide tubes 178 are about four inchessquare in section, have a wall thickness of about ⅜ inch, are about 88inches in height, and are preferably constructed of stainless steel oranother suitable steel. Similarly to mast tubes 176, guide rails 179 aremounted at their inner face to the corners of guide tubes 178 oppositeto the outer corners of mast 13. Rails 179 need not be the full lengthof tubes 178 or 176, but may rather be fixed only to that portion of thetube in contact with a roller.

Remaining with FIGS. 10 and 12, roller assemblies 177 preferablycomprise rollers 192 fixed to mounts 193. Preferably, roller 192 is asteel, yoke-style roller, having a V-groove; such rollers with bearingsrated for 12,000 pound thrust limit were found to be acceptable. Mounts193 are preferably an angled bracket having an adjustable yoke fittingto accept a yoke-style roller and to adjust the position of the rollerwith respect to the rail. Other roller assembly components known to aperson skilled in the art may be acceptable. In a preferred embodiment,mast guide 15 comprises three sets of four roller assemblies 177 each,all of the assemblies in a given set being labeled with the same suffix,177 a-177 c respectively. However, sets need not have four rollerassemblies; while four opposing assemblies are advantageous, twosymmetrically opposed assemblies per set could also be used, forinstance with a further set having such opposed assemblies oriented to adifferent axis than the first, thus guiding the mast in more than oneaxis normal to the translation axis. Each such assembly preferablycomprises one roller 192 and mount 193, and each assembly 177 mounted toeither mast 13 or to guide tubes 178, and placed opposing guide rails179 on either tubes 178 or mast 13. Rollers 192 are in rolling contactwith tubes 178 or mast tubes 176, or preferably, with guide rails 179 onthose tubes. This provides a low-friction manner of transmitting forcesout of the translation axis, here vertical, from mast 13 to guide tubes178. In this manner, roller assemblies 177 inhibit translation of mast13 out of that translation axis.

In a preferred embodiment, a set of lower roller assemblies 177 a aremounted to mast 13, near its bottom using mounts 193, while intermediateroller assemblies 177 b, and upper roller assemblies 177 c are mountedto guide tubes 178 in a fixed relationship to one another, with upperroller assemblies 177 c placed near the upper portion of guide tubes178, also using mounts 193. This permits rollers lower assemblies 177 ato continue to guide mast 13 as it moves upwardly, and avoids the upperassemblies 177 c interfering with upward movement of mast 13.Positioning of sets of roller assemblies 177 along the translation axismay vary as design criteria such as needed height of the mast, orelevation vary, but positioning the set of lower roller assemblies 177 aat or near base plate 174, and positioning the sets of intermediate andupper assemblies 177 b, 177 c about 65 and 86 inches, respectively,above assembly base 21 was found to be acceptable.

Remaining with FIGS. 10 and 12, mast guide 15 preferably furthercomprises reinforcement straps 175. Strap sets 175 should be distributedalong guide 15, and placed at points to oppose lateral forces that mightcause a guide tube to buckle. In one embodiment, three strap sets 175a-175 c are located in positions corresponding to the vertical positionsof sets of roller assemblies 177. In another embodiment, two strap sets175 a′, 175 b′ are roughly evenly spaced along the height of guide tubes178, and are about 30 and 70 inches above assembly base 21,respectively. Strap sets 175 in these embodiments are preferably metalbars, about three inches wide, and about ⅜ inch thick, reaching from oneguide tube 178 to the adjacent guide tube, and welded thereto. Strapsets 175 are made of a metal suitable for welding to guide tubes 178.

Turning to FIGS. 6A, 6C and 6D, mast-head 14 preferably comprisesmast-head plate 97, reinforcement plate 157, mast-head frame 98, boomjoints 99, boom joint supports 100, mast-head cover plate 101, andsheeting 185. In one embodiment, mast-head 14 is constructed ofstainless steel, while in another, it is constructed of galvanizedsteel. An acceptable stainless steel for the components of mast-head 14is 316L stainless steel. Another acceptable steel for the components ofmast-head 14 is a galvanized hot-rolled structural channel steel, suchas ASTM A36 mild steel. Plate 97, in one embodiment, is roughlycoffin-shaped viewed from above (in FIG. 1A), is flat and about ⅜ inchthick, and has forward, middle and rear sections, the first and lastbeing tapered to substantially square ends. Plate 97's length, alignedwith the longitudinal axis of the horizontal boom section, is about 156inches, and is about 48 inches wide at its widest, in the middlesection, which is about 36 inches long. The forward section of plate 97,adjoining horizontal boom section 20, is about 48 inches long, andtapers to about 36 inches wide. The rear section of plate 97, supportingfirst counterweight 16, is about 72 inches long, and tapers to about 36inches wide.

Referring to FIGS. 11 and 16, the middle section of plate 97 has severalholes defined through it, including access hole 156, centered aboveturntable 17, and 90-degree drive hole 161, set slightly off to the sideof hole 156. Preferably, access hole 156 is partially circular about 12inches diameter, having one side, preferably to the side and rear,flattened off chord-wise about two inches. Also preferably, drive hole161 is oval and is aligned along the radial of hole 156 normal to theflattened chord, about four inches from that flattened portion. Drivehole 161 has a minor and major diameters of about six and ten inches.

Referring to FIGS. 6A and 10, reinforcement plate 157 is preferablymounted below mast-head plate 97, in the area in which mast-head 14 issupported by mast 13, and is preferably roughly square, about ½ inchthick, and about 48 inches in length and width, and has the cornersrounded off. In another embodiment mast-head extension 18, supportingsecondary counterweight 19, may be joined to the rear section of plate97, beyond rearframe 184.

Turning to FIGS. 6A, 6C and 6D, mast-head frame 98 lies above thesurface of mast-head plate 97, and preferably conforms substantially tothe periphery of plate 97. Frame 98 comprises a forward transition 181,a middle section 182, a rear transition 183 and rear frame 184. Thepreceding four each comprise upper, middle and lower frames, designatedwith the suffixes a, b and c, respectively. Upper frames 181 a-184 a,and lower frames 181 c-184 c, are preferably five inch C-channel beams,about ¼ inch thick, placed such that the legs of the beams pointinwardly into mast-head 14, and run parallel to the periphery of plate97. More preferably, upper frames 181 a-183 a, and lower frames 181c-183 c, are formed of single pieces of C-channel, having the legsnotched, to permit bending the web at the forward transition 181—middlesection 182 and middle section 182—rear transition 183 junctions. Usingsingle pieces lends strength to these junctions. The lower set of legsof lower frames 181 c-184 c abut plate 97, while the upper set of legsof upper frames 181 a-184 a abut mast-head cover panel 101. Separatingthe “a” and “c” frame sets are middle frames 181 b-184 b, which are alsopreferably 5-inch C-channel beams, but cut to three inch lengths, andset endwise between the upper and lower frames. Middle frames 181 b-184b are welded at their “C”-shaped ends to the lower legs of upper frames181 a-184 a, and the upper legs of lower frames 181 c-184 c,respectively, with the legs of middle frame 181 b-184 b pointed towardthe interior of mast-head 14. Middle frames are located at severallocations along the upper and lower frames, preferably at or near thepoints of transition between forward, middle and rear transitions181-183 and rear frame 184, as well as one or more locationsintermediate thereto.

In one embodiment, each of forward transition frames 181 are about 13inches high, and run about 49 inches along the side edges of the forwardsection of plate 97. Similarly, each of middle section frames 182 areabout 13 inches high, and run about 36 inches along the edge of themiddle section of plate 97, and each of rear transition frames 183 areabout 13 inches high, and run slightly more than about 72 inches alongthe side edges of the rear section of plate 97. Preferably, a singlepiece of channel about 157 inches long is used for upper and lowerframes 181 a-183 a, 181 c-183 c. Rear frame 184 is also about 13 incheshigh and runs about 36 inches along the rear edge of plate 97. Lowerframes 181 c-184 c are preferably both welded and bolted to mast-headplate 97. Mast-head frame 98 also comprises front frame 180, which is atthe front of mast-head plate 97, and is only a portion of the height offrames 181-184, preferably about 3 inches, to accept horizontal boomsection 20. In one embodiment, front frame 180 is 3-inch angle bracket,¼ inch thick; in another, it is a tube having a roughly three-inchsquare hollow section. Preferably, sheeting 185 is mounted to mast-headframe 98 on its outward side, and may comprise ⅛ inch 5052 aluminumsheet.

Mast-head 14 also preferably comprises upper and lower boom joints 99 a,99 b, rear boom joint 207, and boom joint supports 100. Boom joints 99a, 99 b and 207 are beams structurally connecting horizontal boomsection 20 to mast-head 14, and are preferably five inch C-channel,having legs 188 extending from inner surface 186. There are preferablytwo each of upper and lower boom joints 99 a, 99 b, one upper and onelower on each side of horizontal boom section 20, placed alongside andparallel to proximal ends 62 of beams 56, and so that outer surfaces 187of boom joints 99 a, 99 b abut the outer surface of beams 56, and innersurface 186 and legs 188 face away from horizontal boom section 20. In aparticularly preferred embodiment, upper boom joints 99 are about 156inches long, and may be constructed of 304L stainless steel or anotheracceptable steel suitable for welding to mast-head 14. Upper boom joints99 a extend forwardly from rear frame 184 a to the forward end ofmast-head 14, at the forward end of forward transition 181 a. Lower boomjoints 99 b, shorter than the upper ones, extend forwardly from rearboom joint lower joint section 207 c to the forward end of mast-head 14,at the forward end of forward transition 181 c. Boom joints 99 a, 99 bare joined to horizontal boom section 20, preferably by structural bolts206 distributed along its length, and with rear boom joint 207, supportboom section 20, and thereby boom section 22. In addition, angle bracket149, welded to the exterior of forward transitions 181, is placed withone leg flush to the opening for boom section 20, and is bolted to boomsection 20.

Upper boom joints 99 a are supported above lower boom joints 99 b, andabove plate 97, by several boom joint supports 100, and are preferablybraced in that position by several transverse braces 163. Supports 100are preferably sections of five-inch channel, in which the legs runvertically, and support upper beam joints 99 a at their lower legs 188at numerous places along their length. Two transverse braces 163 arepositioned in a transverse relationship with each of upper boom joints99 a, between inner surfaces 186 and mast-head frame 98. Preferably,braces 163 are short sections of 3-inch by ¼ inch angle bracket, and arelocated near proximal ends 62 of beams 56, near the joint betweenforward transition 181 and middle section 182, and near the jointbetween middle section 182 and rear transition 183. Also preferably,rear gussets 191 are joined between boom joint inward surface 187 andupper rear frame 184 a. In a particularly preferred embodiment, braces163 are about six inches in the dimension long, are joined such that thelegs run from inner surfaces 186 to frame 98.

Referring to FIG. 6D, rear boom joint 207 is placed transversely betweenupper and lower boom joints 99 a, 99 b, and immediately rearwardly ofhorizontal boom section 20. Rear boom joint 207 preferably comprisesupper and lower joint sections 207 a, 207 c, and middle section 207 b.Boom joint sections 207 a, 207 c are preferably five inch C-channel, andcomprise distal and proximal faces 209, 210, legs 212 rising from theproximal face, and ends 211. Upper section 207 a further comprisestension cable chases 208, and lower section 207 c, longer than uppersection 207 a, defines cutaway sections 213. Middle sections 207 b aresimilarly five inch C-channel sections, cut to three-inch lengths andjoined to the upper and lower sections in a manner similar to that usedin frames 181-184. Middle sections 207 b are placed to either side ofproximal end 44 of tube 40, which is exposed at flange 66 a. Distalfaces 209 of rear boom joint 207 abut proximal face 68 a of flange 66 a,as well as proximal ends 62 of beams 56. Rear boom joint 207 is joinedto horizontal boom section 20, at these abutting surfaces, preferably byseveral structural bolts 206 distributed across rear boom joint 207.

Turning to FIGS. 14A and 14B, in another embodiment, mast-head extension18, for supporting secondary counterweight 19, is attached to mast-head14. Extension 18 comprises extension plate 217, extension frame 218 andextension cover panel 222. Extension 18 may be either a stainless steelalloy, or galvanized steel, but the material should match that used formast-head 14. Plate 217 is preferably one-inch plate, and about 48inches long, measuring longitudinally from its point of attachment tomast-head 14. The joined end preferably matches the rear end ofmast-head 14 and is about 36 inches wide, while the opposite, rear, endis tapered to about 20 inches wide. Frame 218 comprises extension rearframe 219 and two side frames 220, which preferably extend frommast-head rear frame 184 rearwardly to extension rear frame 219. Rearand side frames 219 and 220 are constructed similar to frames 181-184,using lengths of 5 inch C-channel forming upper frames 219 a, 220 a andlower frames 219 c, 220 c, and short lengths, preferably three inches,of cut channel welded therebetween, forming middle frames 219 b, 220 b.Frame 218 further includes angle bracket 221, preferably 2 by 2 inch by⅜ inch thick, attached to the front edge of plate 217, with a verticalface aligned upwardly at that edge.

Secondary counterweight 19 is mounted, or otherwise fixed, withinextension 18, preferably to plate 217, and preferably as near toextension rear frame 219 as practicable, to maximize thecounterweighting effect. Should secondary counterweight 19 be sufficientto balance instrument boom 10, first counterweight 16 may be omittedentirely. In one embodiment, secondary counterweight 19, comprisingabout 2,400 pounds of lead sheet, was sufficient to balance instrumentboom 10. Frame 218 is mounted to plate 217 by welding the lower leg oflower side frames 220 c and rear frame 219 c to plate 217, and by usingbolts 206 to connect the two components. Mast-head extension 18 ismounted to mast-head 14, preferably by welding the joined, wider, end ofextension 18 to the rear edge of mast-head plate 97 and rear frame 184a-184 c. In a particularly preferred embodiment, the wider end ofextension plate 217 is welded to the rear edge of plate 97, the verticalface of angle bracket 221 is welded to lower rear frame 184 c, and theforward ends of upper and lower side frames 220 a, 220 c are welded tocorresponding upper and lower mast-head rear frames 184 a, 184 c. Coverpanel 222 may be fixed to extension 18 using panel bolts 155. As afurther alternative, plates 97 and 217 may be formed as a single plate.

Referring to FIGS. 6C, 6D and 10, mast-head cover 101 is mounted to andabove mast-head frame 98. Cover 101 is preferably light plate conformingsubstantially in shape to mast-head plate 97, and to the periphery ofmast-head frame 98. In a particularly preferred embodiment, cover 101comprises several ⅛ inch thick aluminum plates, which together areroughly shaped as mast-head plate 97. The various plates of cover 101may be mounted to frame 98 using bolts 155.

Mast-head 14 is preferably constructed as follows. Joinder is preferablyby welding, more preferably by a MIG (gas metal arc) welding process. Awelding process using a 200 ampere MIG welder, manufactured by MillerElectric Mfg. Co., 1635 West Spencer Street, P.O. Box 1079, Appleton,Wis. 54912, has been found to be satisfactory, although a higheramperage rating may be desirable to reduce any need for preheating thealuminum material. A pure argon shielding gas was acceptable. ASPOOLMATIC 30A automatic wire feed system, also by Miller Electric, wasused to feed a 0.035 inch ER 4043 aluminum alloy wire to the MIG welder.If necessary, preheating may be accomplished using an oxy-acetylene orpropane torch. Other methods of accomplishing joinder between metalobjects known to a person of skill in the art may be satisfactory, suchas TIG-type welding, and will depend upon the specific compositions andheat treatment of the materials used. In addition, the above techniquesare suitable for horizontal and vertical boom sections 20, 22, mastassembly 12, and box joint 59.

Referring to FIGS. 6C and 6D, mast-head 14 is constructed in thefollowing preferable sequence: plate 97 is pre-drilled with holes toaccept bolts 206, and is supported for the construction process slightlyhigher at the forward and rear ends to induce a slight “sag” in the areato be joined to middle section 182. This sag is induced to counteractthe hogging effect created by applying the loads to mast-head 14,counterweights 16, 19 and horizontal and vertical boom sections 20, 22at its two ends. A slight, visible, sag at that middle section was foundto be acceptable. The lower legs of lower frames 181 c-184 c of frame 98may also be pre-drilled with holes for bolts 206. Further, referring nowto FIG. 6A, the legs of the single pieces comprising upper frames 181a-183 a and lower frames 181 c-183 c are preferably previously notchedto permit the bends in the web to form the angled transitions betweenforward transition 181 and middle section 182 and between middle section182 and rear transition 183. In addition, one end of the single pieces,and both ends of rear frames 184 a, 184 c, are preferably previouslybevel cut in order to facilitate miter joints at the angled transitionsbetween rear transition 183 and rear frame 184. Tack-welding, andclamping may be utilized in this construction process in order tocounteract heat expansion difficulties.

Returning to FIGS. 6C and 6D, the lower leg of the single piece ofchannel comprising lower frames 181 c-183 c is placed so that itsforward end is aligned with the forward end of plate 97, and permitsproper placement of lower boom joints 99 b. Further, its legs faceinward, and its five-inch face is substantially flush with the edge ofplate 97 in the forward transition, and preferably, its bolt holes arealigned to those in plate 97. Lower frame 181 c-183 c is then weldedalong both the inner and outer edges of the lower leg to the uppersurface of plate 97 in forward transition 181 c. Referring now to FIG.6A, the single piece is then bent to form the angled transition betweenforward transition 181 and middle section 182, and lower frame 181 c-183c is welded along both the inner and outer edges of the lower leg to theupper surface of plate 97 in middle section 182 c. Next, the singlepiece is bent to form the angled transition between middle section 182and rear transition 183, and lower frame 181 c-183 c is welded alongboth the inner and outer edges of the lower leg to the upper surface ofplate 97 in rear transition 183 c. Next, this process is repeated withlower frame 181 c-183 c located on the opposing side of plate 97.Finally, returning to FIGS. 6A, 6C, the lower leg of lower frame 184 cof rear frame 184 is welded along both the inner and outer edges to theupper surface of plate 97, and the beveled edges at the ends of lowerframe 184 c are welded to the beveled ends of the single pieces forminglower frames 181 c-183 c. Once all lower frames 181 c-184 c are weldedin place, they are bolted to plate 97 using bolts 206 (see FIG. 6D).

Next, referring to FIGS. 6C and 6D, proceeding sequentially around lowerframes 181 c-184 c, one C-shaped end of each of middle frames 181 b-184b is welded in place to the upper legs of lower frames 181 c-184 c.Again, the legs of the middle frames 181 b-184 b face inwardly, and theopposing face is aligned with the edge of plate 97. The order in whichthis is accomplished may vary. In one embodiment, there are middleframes located at: the forward end and midpoint of forward transition181, at the junction of forward transition 181 and middle section 182,at middle section 182's midpoint and its junction with rear transition183, three distributed along the length of rear transition 183, at therear of rear transition 183, and at each end of rear frame 184.Placement of middle frames is also visible in FIGS. 14A and 14B.

Next, remaining with FIGS. 6C and 6D, the lower leg of the single pieceof channel comprising lower frames 181 c-183 c is placed above lowerframe 181 c so that its forward end is aligned with the forward end ofplate 97, and permits proper placement of upper boom joints 99 a.Further, its legs face inward, and its five-inch face is substantiallyflush with the edge of plate 97 in the forward transition. Upper frame181 a-183 a is then welded to the second C-shaped ends of middle frames181 b in the forward transition. Then, turning to FIG. 6A, the singlepiece is bent to form the angled transition between forward transition181 and middle section 182, and the lower leg of upper frame 181 a-183 ais welded to the second C-shaped ends of middle frames 182 b in themiddle section. Next, the single piece is bent to form the angledtransition between middle section 182 and rear transition 183, and upper181 a-183 a is welded is to the second C-shaped ends of middle frames183 b in the rear transition. Next, this process is repeated with upperframe 181 a-183 a located on the opposing side of plate 97. Finally, thelower leg of upper frame 184 a of rear frame 184 is welded to the secondC-shaped ends of middle frames 184 b in the rear transition, and thebeveled edges at the ends of upper frame 184 a are welded to the beveledends of the single pieces forming upper frames 181 a-183 a.

Next, turning to FIGS. 6C and 6D, rear boom joint lower frame 207 c,which like the lower frames, has preferably been pre-drilled, is alignedforward of access hole 156 (in FIG. 6A) to corresponding bolt holes inplate 97. Lower frame 207 c is placed with its legs 212 c at ends 211 cabutting the legs at the forward ends of lower frames 182 c. The lowerleg 212 c of lower frame 207 c is then welded in place to plate 97, andbolts 206 are installed. Welds on upper, lower or rear boom joints 99 a,99 b, 207 on outer surfaces 187, or on distal faces 207 a-207 c, shouldbe avoided, at least those at or above three inches above mast-headplate 97. These surfaces are preferably left smooth for a close fit tohorizontal boom section 20. However, if necessary these surfaces may bewelded upon, if appropriate finishing measures, such as beveling andgrinding, are used to ensure a smooth surface.

Next, remaining with FIGS. 6C and 6D, one of lower boom joints 99 b,like 207 c preferably pre-drilled, is aligned with the bolt holes inplate 97, which places boom joint 99 b's forward end flush with theforward end of plate 97, and in contact with lower frame 181 c, and itsrear end abutting distal face 209 of lower rear boom joint 207 c. Outersurface 187 faces inward, away from frame 98. Legs 188 at the forwardend of lower boom joint 99 b may be trimmed away to form a good jointwith lower frame 181 c, and to obtain the proper positioning; it isimportant that the distance between boom joint outer surfaces 187, forboth upper and lower boom joints 99 a, 99 b, is matched closely to theoverall width of horizontal boom section 20, in order to obtain a snugfit and deter “wobbling” of instrument boom 10. This width may varydepending upon material chosen for construction, but in one embodimentusing a stainless steel for construction of mast-head 14, 25.125 incheswas found acceptable for the distance between surfaces 187. To accountfor the galvanized layer's thickness, a slightly greater distance may beneeded if galvanized steel is used. Lower leg 188 of boom joint 99 b iswelded to plate 97, its rear end to lower rear boom joint 207 c, and itsforward end to lower frame 181 c. Lower leg 188 is then bolted to plate97. This process is then repeated with the other lower boom joint 99 b.

Next, the several supports 100 are fixed in place. Referring to FIGS.6A, 6C and 6D, supports 100, preferably twelve, are located as follows.A first six are cut to three-inch length: two each between upper andlower boom joints 99 a, 99 b, near forward end 189 of upper beam joints99 a about at the midpoint of lower boom joint 99 b, and at the junctionof lower boom joint 99 b and lower rear boom joint 207 c. A second sixare cut to eight-inch length: two each about even with sheave support154, about at the transition between middle section 182 and reartransition 183, and about at the midpoint of rear transition 183. FIGS.14A and 14B also depict placement of some of supports 100. All supports100 are placed with their legs pointed outwardly, and the 5-inch faceinwardly. The first six, three-inch supports, are welded at one C-shapedend to the upper of lower boom joint legs 188, the last extending ontothe upper of rear boom joint legs 212 c. The second six, eight-inchsupports are welded at one C-shaped end to plate 97, in two linesextending rearwardly from lower boom joints 99 b.

Next, remaining with FIGS. 6A, 6C and 6D, one of upper boom joints 99 ais added. With outer surface 187 facing inwardly, away from frame 98,forward end 189 of boom joint 99 a is placed above lower boom joint 99b's forward end, supported on the lower of legs 188 by supports 100.Forward end 189 should be flush with the forward end of plate 97, and incontact with upper frame 181 c. Rear end 190 will abut the legs of upperrear frame 184 a. Legs 188 at forward end 189 of upper boom joint 99 amay be trimmed away to form a good joint with upper frame 181 a, forreasons noted above. Then, the lower of legs 188 are welded to theC-shaped ends of supports 100, and forward and rear ends 189, 190 arejoined to upper frame 181 a and upper frame 184 a, respectively. Theweld to upper frame 184 a may be made on boom joint outer surface 187.This process is then repeated with the other upper boom joint 99 a.

Turning to FIGS. 6A and 11, four transverse braces 163 are added; theyare placed between upper boom joints 99 a and upper middle sectionframes 182 a, two at the forward ends and two at the rear ends, offrames 182 a. The ends of braces 163 join boom joint inner surface 186and the inner face of frames 182, between the legs, and are weldedthereto.

Turning to FIGS. 6D, rear boom joint middle frames 207 b are placed toeither side of center of lower frame 207 a, leaving a gap between themof at least about five inches. One C-shaped end of each of middle frames207 b is joined to the upper of legs 212 by welding, with legs 212 ofmiddle section 207 b facing rearwardly.

Next, upper frame of rear boom joint 207 a is added, the lower of itslegs 212 joined to the top of the second C-shaped ends of middle frames207 b, and its C-shaped ends 211 c abutting and joined to boom jointouter surface 187. Next, in FIG. 6C, angle brackets 149 are welded tothe forward ends of frames 181 a, 181 c and boom joints 99 a, 99 b.Finally, sheeting 185 is joined to the outer surfaces of frames 181-184,preferably by riveting, and mast-head cover plate is added using bolts155 fixed preferably to upper legs of frames 98 or upper boom joints 99a.

Turning to FIGS. 10 and 11, mast-head 14 is preferably supported byturntable 17. Mast-head plate 97 is mounted to reinforcement plate 157below, and thence to upper plate 159. Reinforcement plate 157distributes the load applied by upper plate 159. Turning to FIG. 16,turntable 17 is itself supported on mast 13 by lower plate 158 androtary bearing assembly 160. Bearing assembly 160 has diameter d7, whichis preferably about 30 inches and is suitable for supporting a load ofabout 40,000 pounds. Turntable 17 permits rotation of mast-head 14relative to mast 13, and thus to transport body 8, and movement axis 5.

Remaining with FIGS. 10 and 11, mast rotation motor 88, reducer 89 and90-degree drive 90 are mounted within mast-head 14, to mast-head plate97, either directly or indirectly. Motor 88 is joined to reducer 89using a shaft, and preferably operates at about 1140-1180 R.P.M. Reducer89 provides a reduced output shaft R.P.M., preferably a ratio of about1:6000. Output speed of reducer 89 is preferably such that deploying ofinstrument boom 10 occurs at about 15 degrees per minute. Reducer 89'soutput shaft is joined to a wire cage coupling 193 (in FIG. 15), whichcomprises a cover, a first toothed transmission disk 194 a, coupled toreducer 89, and offset a short distance along the shaft's axis, a secondtoothed transmission disk 194 b, joined by a shaft to the input of90-degree drive 90. Wire cage 195 is formed by tightly looping wirearound the teeth of one transmission disk and around the teeth of thesecond, and repeating the process with other teeth, until each tooth isbound to one or more teeth with one or more loops of wire. Such a wirecage coupling 193 is advantageous because it provides a lower torqueloss than a conventional rubber bushing, and little backlash. A modelRK6-25N12 turntable bearing by Kaydon Corp., having an outer diameter of29.5 inches, was found to be acceptable. A ½ H.P. SM-Cyclo 4000 electricmotor was found to be acceptable for mast rotation motor 88. A Sumitomomodel no. CHHJ4145DB4-7569 was found to be acceptable for reducer 89,and HUB CITY brand 90-degree drive, providing a 1:1 ratio, was found tobe acceptable for drive 90.

Turning to FIGS. 11 and 16, drive 90 translates the output shaftrotation from coupling 193 to rotation in a second shaft in the verticalplane via a gearset (not shown). An output shaft from drive 90, passingthrough drive hole 161, is fixed to spur gear 196, which drives ringgear 197 fixed to lower plate 158 of turntable 17. As drive 90 is fixedto mast-head 14, and ring gear 197 to lower plate 158, and thence tochassis 6 via mast 13, operation of mast rotation motor 88 results inrotation of instrument boom 16. Rotation is permitted at least betweenthe deployed position in FIG. 1C and the stowed position in FIGS. 2A and2B. The deployed position in the preferred embodiment is about tendegrees rearward of a position normal to movement axis 5, while thestowed position is rearward and about thirteen degrees off movement axis5.

Returning to FIGS. 1A and 1B, operator compartment 107, preferablylocated in the rearward portion of transport body 8, includes operatorstation 110, which permits an operator to control items such asinstrument boom 10, emitter 112 and low-speed drive system 120. Drivesystem 120 may also be controlled by a driver in cab 4. Furtherequipment found in the preferred embodiment include video cameras 118and worklights 119, which may also be operated from operator station110.

Steady and slow forward movement of mobile inspection unit 1 alongmovement axis 5 (in FIG. 1A) is desirable for several reasons. First, inoperation, a driver in cab 4 will control the direction of movementalong movement axis 5 using a conventional, installed, steering system,just as along a roadway during normal movement. The driver or theoperator at station 110 would operate low-speed drive system 120 tocontrol the speed of inspection unit 1. In operation, side clearance 128(in FIG. 1C) may be as little as 21 inches, depending upon the size oftarget 131 and the size of instrument boom 10. Thus, slow forward motionpermits the driver to maintain this clearance more easily. Further, slowpassage will increase the amount of time in which any particular portionof target 131 remains within scanning zone 114, increasing likelihood ofdetection of the sought after contraband or other items. In addition,accuracy is increased, as a smooth forward motion will minimize jerkingassociated with use of a conventional transmission of main drive system3. Jerking would likely result in motion and flexure of instrument boom10 relative to emitter 112, with resultant inaccuracies of detectionbased upon received signals. In a preferred embodiment, movement ofinstrument boom 10 relative to emitter 112, as measured at distal end 29a of lower boom segment 26 (visible in FIG. 1D), should be less thanabout one inch in any direction.

Turning to FIG. 2B, to permit such steady and slow forward movement,low-speed drive system 120 is preferred to power a rear set of wheels 7.Low-speed drive system 120 utilizes electric power from generator 102 topower electric motor 121. Motor 121 may run at up to 2000 RPM, and thusreducer 122 is used to reduce the rotational speed transmitted from theshaft of motor 121. From reducer 122, power is transferred, via transfercase 124, to reversed differential 123. Differential 123 convertsrotation transverse to the axle of the shaft of reducer 122 to drive therear set of wheels 7 of mobile transport 2, and is directed from therear of wheels 7 in order not to interfere with main drive system 3.During operation, an operator at operator station 110, or the driver incab 4 (both visible in FIG. 1A), can control the speed of motor 121 topropel mobile transport 2 at various speeds past a target 131; further,speed may be closely controlled because electric motor 121's speed maybe adjusted up and down in small increments. These speeds may range fromabout 15 inch/second to about 60 inch/second. Transfer case 124 permitsmotor 121 and reducer 122 to be completely disengaged from reverseddifferential 123, permitting the rear set of wheels 7 to rotate freelyduring periods when mobile transport 2 is being propelled by main drivesystem 3. In the preferred embodiment, low-speed drive system 120incorporates a conventional interlock preventing it from being engagedif main drive system 3 is engaged. Main drive system 3 similarlyincorporates a conventional interlock to prevent it from being engagedif low-speed drive system 120 is engaged.

In order for mobile inspection unit 1 to most accurately inspect targetvehicles or cargo, instrument boom 10 should provide a high degree ofrigidity and torsional resistance. As discussed, rigidity and torsionalresistance is important to maintain proper alignment between sensorpackages 24 and emitter 112. Mast-assembly 12, particularly mast-head14, and horizontal boom section 20, support much of the load applied bythe sensors and the weight of instrument boom 10, both vertical andtorque, and provide much of that rigidity.

Turning to FIGS. 6A and 6B, horizontal boom section 20 compriseslongitudinal and transverse axes 21 a, 21 b, and a first support member,preferably inner tube 40, having outer surface 42, and longitudinal axis41, proximal end 44 and distal end 46. Preferably, longitudinal axis 41is coincident with axis 21 a. Although the first support member isdescribed and depicted as a hollow tube or cylinder, it could also be asolid rod; however a hollow tube has the advantage of providingadditional torsional resistance compared to a solid rod of identicalunit weight. Similarly, while inner tube 40 is depicted as beingcircular in cross section, it could also be oval or some other annularcross section. Further, the configuration will depend upon the specificmaterials utilized and the loads to be applied. In a preferredembodiment, inner tube 40 is formed as a hollow aluminum cylinder,having an annular cross-section, and an outer diameter d1, thickness t1and length n1. In a particularly preferred embodiment, d1 is about 4inches, t1 is about ½ inch, n1 is about 200 inches, and inner tube 40 isconstructed of T6 6061 aluminum. While ANSI type T6 6061 aluminum hasbeen found to be acceptable for tube 40, and for other components, othertypes of heat-treated or high-strength aluminum, or other metals may beacceptable depending upon the design criteria.

Continuing with FIGS. 6A, 6B and 8A, horizontal boom section 20 alsocomprises a plurality of second support members, preferably eleven outertube segments, 48 a-48 j; however the number and length of such segmentsmay vary upwardly from one, and will depend upon the specific materialsutilized and the loads to be applied. Outer tube segment 48 a hassurface 50 a, proximate end 52 a and distal end 54 a. Similar featureson outer tube segments 48 a-48 j are labeled utilizing those respectivesuffixes. Outer tube segments 48 a-48 j may be of a non-circular crosssection, and may be of a different cross-sections or length from oneanother, however their inner dimensions must be larger than outerdiameter d1 of inner tube 40. In a preferred embodiment, outer tubesegments 48 a-48 j are formed as hollow aluminum cylinders, each havingan annular cross-section, and an outer diameter d2 and thickness t2.Segments 48 a-48 j have lengths n2a through n2j, respectively. In apreferred embodiment, d2 is about 8 inches, t2 is about ½ inch, n2athrough n2c are about 15½ inches, n2d is about 9½ inches, n2e throughhn2i are about 23½ inches, and n2j is about 21½ inches. The number ofsegments, and their exact dimensions may vary, depending upon designcriteria. In another embodiment, only nine segments are used, andlengths n2a through n2c are adjusted to compensate, preferably byincreasing them to about 18½ inches. Preferably, outer tube segments 48a-48 j are constructed of 6061 T6 aluminum, although other materials maybe acceptable.

Turning now to FIGS. 6A, 6B and 8, horizontal boom section 20 alsocomprises third support members, preferably beams 56, having one or morelegs 58 a and 58 b, and inward surface 60. In a preferred embodiment,beams 56 are C-channel beams constructed of aluminum, and are also shownin FIG. 4. Also in this embodiment, inward surface 60 lies between legs58 a, 58 b, which rise from the planar surface of beam 56, and run downits longitudinal axis. Beams 56 also have proximal end 62 and distal end64. In this preferred embodiment, beams 56 have height h3, thickness t3and legs 58 a, 58 b have depth x3. In this preferred embodiment, distalend 64 extends about 10 inches beyond flange 66K to facilitate box joint59. In a particularly preferred embodiment, h3 is about 10 inches, t3 isabout 0.5 inch, x3 is about five inches, n3 is about 210 inches, andbeams 56 are constructed of 6061 T6 aluminum.

Horizontal boom section 20 also comprises a number of HBS flanges 66,arrayed in a spaced relationship to one another. Referring to FIGS. 6Aand 6B, in a preferred embodiment there are eleven HBS flanges 66 a-66k. HBS flanges 66 a and 66 k may be referred to as end caps due to theirterminal positions on horizontal boom section 20 and inner tube 40.Turning to FIGS. 4, 5A and 5B, HBS flange 66 b includes proximal face 68b, and distal face 70 b, as well as upper edge 72 b, lower edge 73 b andside edges 74 b. HBS flange 66 b also incorporates flange hole 76 bwhich has flange hole edge 77 b, and proximal and distal grooves 78 b,79 b, located respectively upon proximal and distal faces, 68 b, 70 b.Grooves 78 b, 79 b are circular, and concentric to flange hole 76 b, andcorrespond to the dimensions of outer tube segments 48. Grooves 78, 79are preferably included, as they aid alignment of outer tube segments 48during assembly and construction of horizontal boom section 20, however,they could be omitted, with the lengths of the outer tube segmentsreduced commensurately, and proximal and distal ends 52, 54 abuttingdirectly upon faces 70, 68 of HBS flanges 66. Grooves 78 b, 79 b have anouter diameter corresponding to diameter d2, and the groove has athickness corresponding to thickness t2. Further, grooves 78 b, 79 bhave depth g4, from the face inward, sufficient to permit acorresponding distal end 54 a of tube segment 48 a or proximal end 52 bof segment 48 b to be inserted therein, and for the segments to besupported therein. In a preferred embodiment, d2 is eight inches, t2 is½ inch and g4 is about ¼ inch.

HBS flange 66 b also preferably includes channel cuts 75 b, which, inone embodiment, are relatively shallow depressions formed in upper andlower edges 72 b, 73 b, about ¾ inch deep into the edges, and about fourinches along the edges, and preferably closely conform to the shape ofinward surface 60 and legs 58 a, 58 b of beams 56 to permit congruentengagement therewith. HBS flange 66 b also incorporates two cable chases80 b permitting passage of tensioning cable 150. In a preferredembodiment, there are two cable chases, one each to the sides of flangehole 76 b. In a preferred embodiment, HBS flange 66 b is constructed ofaluminum plate. Flange hole 76 b and cable chases 80 b can be removed byvarious machining processes for cutting thick metal pieces known topersons of skill in the art, such as a plasma cutter, or a water jetcutter. In this embodiment, HBS flange 66 b has height h4, thickness t4and width w4. Flange hole 76 b has diameter d4, and cable chases 80 bhave diameter c4. In a particularly preferred embodiment, flange 66 b isconstructed of 6061 T6 aluminum, h4 is about 10 inches, t4 is about oneinch, w4 is about 23 inches, c4 is about 1½ inches, and d4 is slightlygreater than d1, about 4{fraction (1/16)} inches. HBS flanges 66 a, 66c-66 k have similar features labeled using those respective suffixes.HBS flange 66 b will ordinarily be typical, save for the varyingposition of cable chases 80 a-80 k, but need not be. In addition, endcaps 66 a, 66 k, which only adjoin one outer tube segment apiece, willordinarily omit proximal groove 78 a and distal groove 79 k,respectively. Flange holes 76 a-76 k should be aligned to an axiscoincident to axis 41. Returning to FIGS. 6A and 6B, in a particularlypreferred embodiment, the spacing between the opposing distal andproximal faces of adjacent HBS flanges (e.g. a-b is between distal face70 a and proximal face 68 b, preferably corresponding to a distanceabout ½ inch less than lengths n2a-n2j of outer tube segments 48 a-48 j)is as follows: a-b through c-d, about 15 inches; d-e, about 9 inches;e-f through j-k, about 23 inches. The number of flanges, and the spacingbetween them may vary, depending upon design criteria, such as thelengths of the outer tube segments. In another embodiment, only ninesegments are used, and thus there are only ten flanges, in which casethe spacing is adjusted to compensate.

To accommodate passage of tensioning cable 150 through each of flanges66 a-66 k, as cable 150 moves downwardly and outwardly from proximal endcable attachment 151 to sheave 153 toward distal end cable attachment152, each successive cable chase 80 is at a lesser height above theflange's lower edge 73 (visible in FIG. 8A). Tensioning cables 150provide an upward force upon proximal and distal end attachment points151, 152. Cables 150 are preferably ⅝ inch braided stainless steelcables, and are terminated by threaded studs, which in one embodiment,are about 1¼ inches in diameter, and may be secured by use of hardwareknown to a person of ordinary skill. The upward force is transmittedfrom those attachment points to rear frame 184 of mast-head 14 and toterminal flange 198 and ears 146 of vertical boom section 22.

Turning to FIGS. 10 and 11, sheaves 153, preferably used to redirectcables 150, cause the tension in cables 150 to act upwardly upon thestructure at its ends. Sheaves 153 are located near the center ofmast-head 14, preferably adjacent to access hole 156, and are supportedby supports 154. Sheaves 153 are preferably about five inches indiameter, and supported upon a 1¼ inch bolt. Sheave supports 154 raisesheaves 153 above plate 97, and are preferably square tubing, having afour-inch hollow square section and ⅜ inch wall thickness, cut to abouteleven inches long, onto which sheave 153 is mounted. The upward forcesserve to reduce the “hogging” effect caused by supporting mast-head 14,counterweights 16, 19 and horizontal and vertical boom sections 20, 22at an intermediate position, rather than at their ends. In addition,application of differing tension to cables 150 permits inducement of a“twist” of horizontal boom section 20 along its longitudinal axis. Suchan induced twist may be used to counteract small misalignments of boomsections 20 and 22 during construction or otherwise. Tensioning cables150 are internal to mast-head 14 and horizontal boom section 20, and aresubstantially horizontal, as sheaves 153 provide an upward deflection ofabout eleven inches above plate 97.

Returning to FIG. 4, horizontal boom section 20 preferably also includesupper HBS panels 81, which have edges 82. Preferably, HBS panels 81 aresufficiently wide to run from upper leg 58 b of one beam 56 to upper leg58 b of the opposing beam 56, and together run the length of horizontalboom section 20. Panels 81 are mounted to legs 58 b, preferably usingbolts 155. Panels 81 provide access to the interior of horizontal boomsection 20, protect the cabling and other components of the instrumentboom 10, and are preferably made of about ⅛ inch aluminum sheet.Further, in a preferred embodiment, sensor packages 24 are mounted tobrackets 162, preferably by welding, which are in turn mounted to theunderside of legs 58 b, preferably using bolts 155. Interior face 86 ofsensor packages 24, and the interior of brackets 162 span the gapbetween legs 58 a. In a preferred embodiment, sensor packages 24 andbrackets 162 substantially cover the lower surface of legs 58 a, andextend for substantially all of the portion of the underside ofhorizontal boom section 20 not covered by mast-head plate 97.

Horizontal boom section 20 is preferably assembled and joined by thefollowing method. Joinder is preferably by MIG welding, as above.Referring to FIGS. 4 and 6B, prior to any welding, one of beams 56 islaid on the flat outer surface, with inward surface 60 and legs 58 a, 58b facing upwardly. HBS flange 66 a is aligned to proximal end 62, withside edges 74 a of flange 66 a abutting inward surface 60 and with upperand lower legs 58 a, 58 b congruently engaging channel cuts 75 a. Next,flanges 66 b-66 k are placed with side edges 74 b-74 k abutting inwardsurfaces 60, and with upper and lower legs 58 a, 58 b congruentlyengaging channel cuts 75 b-75 k. Flanges 66 b-66 k, however, are notaligned to their final locations as indicated in FIGS. 6A, 6B, butrather are displaced about eight inches towards distal end 64 of beams56, with flange 66 k being located near distal end 64. Clamps may beused to retain flanges 66 in position. Next, the second of beams 56 isaligned parallel to the first, with inward surfaces 60 facing oneanother, and placed on top of the exposed side edges 74 a-74 k. Thisbeam 56 is fitted to the flanges, side edges 74 a-74 k abutting inwardsurface 60, and upper and lower legs 58 a, 58 b congruently engagingchannel cuts 75 a-75 k. The entire assembly is then compressed, beams 56pressed firmly onto channel cuts 75 a-75 k; again, clamps may be used toretain flanges 66 in position. This assembly is then turned so that isrests upon lower legs 58 a and lower edges 73 a-73 k.

Remaining with FIGS. 4 and 6B, inner tube 40 is then inserted intoflanges 66 at flange holes 76 a-76 k, starting at hole 76 k. Surface 42,at proximal end 44 of tube 40, is aligned with hole 76 k, and thenpushed into it from distal face 70 a. Once proximal end 44 has emergedfrom distal face 70 a, outer tube segment 48 j is interposed betweenflanges 66 k and 66 j, and inner tube 40 pushed therethrough. Tube 40then reaches distal face 70 b of the next flange 66 j. Outer tubesegment 48 j is permitted to rest, or hang, loosely upon surface 42 oftube 40. This process is then repeated until proximal end 44 of tube 40is substantially aligned to proximal face 68 a, of end cap 66 a.

Once in position, flange 66 a is joined to surface 42 of inner tube 40.A weld bead is laid along the interface of flange hole edge 77 a andsurface 42 at either or both of proximal face 68 a or distal face 70 a.Flange 66 a may now be welded to beams 56, first inward surface 60 ofone of beams 56, welded to side edge 74 a, and then the other, byapplying a bead along the interface therebetween, on first proximal face68 a, then distal face 70 a. Next, outer tube segment 48 a is placed ina concentric position outside inner tube 40 (also visible in FIG. 8A),with proximal end 52 a fitting into distal groove 79 a on flange 66 a.Next, the adjacent flange 66 b is moved towards flange 66 a from itsdisplaced position, so that distal end 54 a of segment 48 a fits intoproximal groove 78 b on flange 66 b. In this way, outer tube segment 48a is supported by the two adjacent flanges 66 a, 66 b by grooves 79 a,78 b, and preferably fits therein the full ¼ inch depth. Next, edges 74b of flange 66 b are partially welded to inward surface 60 at distalface 70, using one- or two-inch bead lengths. Next, ends 52 a, 54 a arepreferably also partially welded, using one- or two-inch bead lengths,to distal face 70 a and proximal face 68 b to retain outer tube segment48 a in position. Partial welding of the HBS flanges and the outer tubesegments permits some flex, or “give” so that should there be any needto adjust their alignment, or to adjust the alignment of the structure,that may more easily be done. Further, should the structure begin to bowdue to the welding process, it also permits using a reverse weldingsequence when finishing the weld to cancel out the bowing effect.

Continuing with FIG. 6B, flange 66 b is joined to inner tube 40'ssurface 42. A weld bead is laid along the interface of flange hole edge77 b and surface 42 at distal face 70 b, because proximal face 68 b iscovered by tube segment 48 a. Then, repeating the above sequence, outertube segment 48 b is placed in a concentric position outside inner tube40, with proximal end 52 b fitting into distal groove 79 b on flange 66b. Next, the adjacent flange 66 c is moved towards flange 66 b from itsdisplaced position, enabling distal end 54 b of segment 48 b to fit intoproximal groove 78 c, and flange 66 c and tube segment 48 b arepartially welded into position. This process is repeated for flanges 66d-66 k, and for tube segments 66 c-66 j, sequentially welding the innertube to a first flange, fitting a tube segment to the groove of thefirst flange, sliding the second flange into position and fitting itsgroove to the segment, and welding the flange and tube segment intoplace. Finally, end cap 66 k is placed adjacent to tube segment 48 j,and groove 78 k fitted to end 54 j. Distal face 70 k of flange 66 k willbe aligned substantially to distal end 46 of tube 40, and will be aboutten inches short of distal ends 64 of beams 56. Finally, the partialwelds between HBS flanges 66 and beams 56, and between tube segments 48and flanges 66 are filled in, completing the welds. A reversed weldingsequence may be used to counteract bending due to welding, if needed.Naturally, this process could be accomplished in reverse order,beginning with placement of inner tube 40 into HBS flange 66 a, or withthe flanges initially displaced toward proximal end 62 of beams 56.

Next, proximal ends 52 a-52 j of outer tube segments 48 a-48 j arewelded to distal faces 70 a-70 j, and distal ends 54 a-54 j are weldedto proximal faces 70 b-70 k. Finally, flange 66 b may now be welded tobeams 56, inward surface 60 of one of beams 56, and then the other,welded to side edge 74 b, by applying a bead along the interfacetherebetween, preferably on both of proximal face 68 b and distal face70 b. This process may be repeated until both of beams 56 are welded toeach of side edges 74 a-74 j. However, the sequence in which the edgesare welded to the beams may be varied, such as by alternating edges, orby welding opposing edges first. Similarly, flanges 66 may be joined tobeams 56 prior to welding outer tube segments 48 to flanges 66. Theparticular order may be affected by the need to counteract the effectsof heat expansion, which may vary with ambient temperature. Next,referring to FIG. 4, panel 81 and brackets 162 are mounted using bolts155.

Vertical boom section 22 preferably comprises lower boom segment 26 andupper boom segment 28. Referring to FIGS. 3 and 9, segments 26, 28preferably comprise longitudinal and transverse axes 25 a, 25 b and 27a, 27 b, respectively. Upper boom segment 28 has distal and proximalends 29 b, 30 b, and includes beam segments 139 b, which have beamsegment ears 146, longitudinal axes 140, inward surface 141 a, proximalend 142 a and distal end 143 a. Lower boom segment 26 has distal andproximal ends 29 a, 30 a, and includes beam segments 139 a, which havelongitudinal axes 140, inward surface 141 b, proximal end 142 b anddistal end 143 b. Beam segments 139 a, 139 b may also have one or morelegs, preferably inner leg 144 and outer leg 145. In a preferredembodiment, beam segments 139 a, 139 b are C-channel beams having inwardsurface 141 between legs 144, 145, which rise from the planar surface ofbeam segments 139 a and 139 b, and run down their longitudinal axes. Inthis preferred embodiment, beam segments 139 a, 139 b have width w6,thickness t6, inner and outer legs 144, 145 have depth x6, and beamsegment 139 b has length n6b. In this preferred embodiment, outer legs145 of beam segments 139 b are extended past VBS flange 134 a to formears 146. In a particularly preferred embodiment, w6 is about teninches, t6 is about ½ inch, x6 is about five inches, and n6b is about 85inches. Also in this embodiment, beam segment 139 a, n6a, is about 84inches, not including ear 146. However, beams 56 and beam segments 139 aand 139 b may also omit ears 146 used to construct box joint 59, byutilizing other methods of joining perpendicular beams known to personsof skill in the art. Beam segments 139 a, 139 b are preferablyconstructed of 6061 T6 aluminum.

Referring to FIG. 9, upper and lower boom segments 28, 26 furthercomprise several VBS flanges 134, in a spaced relationship relative toone another (depicted in FIGS. 1D and 9). In a preferred embodiment,there are VBS flanges 134 a-134 i, the first five on upper boom segment28, and the latter four on lower boom segment 26. Referring also toFIGS. 7A and 7B, VBS flange 134 a includes outer edge 136 a, inner edge135 a, side edges 137 a, proximal face 172 a and distal face 173 a. VBSflange 134 a further incorporates one or more flange holes 170 a, flangehole edge 171 a, and channel cuts 138 a. In a preferred embodiment,channel cuts 138 a are relatively shallow depressions formed in innerand outer edges 135 a, 136 a, about ¾ inch deep into the edges, andabout four inches along the edges, and preferably closely conform to theshape of inward surface 141 a, 141 b and legs 144, 145 of beam segments139 a, 139 b to facilitate congruent engagement therebetween (see FIG.3). In a preferred embodiment, VBS flange 134 a has two flange holes 170a, spaced apart, and is constructed of aluminum plate, as with HBSflanges 66. VBS flanges 134 b-134 i comprise similar elements labeledusing those respective suffixes. Flange holes 170 a-170 i should bealigned parallel to axes 25 a, 27 a. Referring to FIGS. 8A, 8B and 9, ina preferred embodiment, in upper boom segment 28, flange 134 a islocated near proximal end 142 b of beam segments 139 b, but below ears146, flange 134 e is located at distal ends 143 b, and flanges 134 b-134d are spaced therebetween. Remaining with FIG. 9, similarly, on lowerboom segment 26, flange 134 f is located at proximal end 142 a of beamsegments 139 a, and flange 134 i is located at distal ends 143 a, whileflanges 134 g, 134 h are spaced therebetween. Turning to FIGS. 7A and7B, in this embodiment, VBS flange 134 a has height h5, thickness t5,width w5, and flange hole 170 a has diameter d5. In a particularlypreferred embodiment, VBS flange 134 a is constructed of 6061 T6aluminum, h5 is about nine inches, t5 is about one inch, d5 is about4{fraction (1/16)} inches, and w5 is about 24 inches. Flange 134 a willordinarily be typical of VBS flanges 134 a-134 i, but need not be, whichmay differ depending upon design criteria for the segments. Returning toFIGS. 1D and 9, in a particularly preferred embodiment, the spacingbetween the opposing distal and proximal faces of adjacent VBS flanges(e.g. a-b is between distal face 173 a and proximal face 172 b) is asfollows: a-b through d-e, about 23.5 inches; and f-g through h-i, about22 inches. VBS flanges are spaced enough to accommodate hinge 31.

Referring to FIGS. 3 and 9, upper and lower boom segments 28, 26 eachfurther comprise one or more upper and lower vertical tube segments 165a, 165 b, respectively, and in a preferred embodiment, two each.Vertical tube segments 165 a, 165 b, as with inner tube 40, aredescribed and depicted as hollow tubes, however, other shapes orcross-sections may be suitable, such as a solid rod, depending upon thedesign. Upper vertical tube segments 165 a have proximal end 166 a,distal end 167 a, surface 168 a and longitudinal axis 169 a. In apreferred embodiment, vertical tube segments 165 a are formed as hollowaluminum cylinders, having an annular cross-section, and outer diameterd8a, thickness t8a and length n8a. In a particularly preferredembodiment, d8a is about 4 inches, t8a is about ½ inch, and n8a is about98 inches, and inner tube 40 is constructed of 6061 T6 aluminum. Tubesegments 165 b have similar features labeled with the suffix b, andwhile upper tube segments 165 a are ordinarily typical, they may differbased upon design criteria; in addition, in a preferred embodiment, n8bis shorter than n8b, and is about 70 inches. Also in a preferredembodiment, axes 169 a, 169 b are parallel to upper and lower boomsegment axes 27 a, 25 a.

Remaining with FIG. 3, vertical boom section 22 preferably also includesouter VBS panels 83, which have edges 84. Preferably, VBS panels 83 aresufficiently wide to reach between opposing legs 145 of each of beamsegments 139 a and 139 b, and together run the length of vertical boomsection 22. Panels 83 are mounted to legs 145, preferably using bolts155. Panels 83 provide access to the interior of vertical boom section22 and protect the cabling and other components of the instrument boom10, and are preferably made of about ⅛ inch aluminum sheet. Further,similarly in a preferred embodiment, sensor packages 24 are mounted tobrackets 162, preferably by welding, which are in turn mounted to theunderside of inner legs 144 of each of beam segments 139 a and 139 b,preferably using bolts 155. In a preferred embodiment, interior face 86of sensor packages 24 and brackets 162 substantially cover the exteriorsurface of legs 144, and have a small gap located at the junctionbetween flanges 134 e and 134 f.

Vertical boom segments 26, 28 are preferably constructed in thefollowing fashion, using tools described above for horizontal boomsection 20. Referring to FIGS. 3 and 9, for upper boom segment 28, priorto any welding, an assembly process similar to horizontal boom section20 occurs. One of beam segments 139 b is laid on the flat outer surface,with inward surface 141 b and legs 144, 145 facing upwardly. Proximalface 172 a of VBS flange 134 a is substantially aligned to proximal end142 b of beam segment 139 b, with ears 146 extending beyond flange 134a. Side edges 137 a of flange 134 a abut inward surface 141 b and innerand outer legs 144, 145 congruently engage channel cuts 138 a. Next,flanges 134 b-134 e are similarly placed between inner and outer legs144, 145, with side edges 137 b-137 e abutting inward surface 141 b andwith inner and outer legs 144, 145 congruently engaging channel cuts 138b-138 e. Distal face 173 e of flange 134 e is substantially aligned todistal ends 143 b of beam segments 139 b. Clamps may be used to retainflanges 134 in position. Next, the second of beam segments 139 b isaligned parallel to the first, with inward surfaces 141 b facing oneanother, and placed on top of the exposed side edges 137 b-137 e. Thisbeam 139 b is fitted to the flanges, side edges 137 b-137 e abuttinginward surface 141 b, and inner and outer legs 144, 145 congruentlyengaging channel cuts 138 a-138 e. The entire assembly is thencompressed, beam segments 139 b pressed firmly onto channel cuts 138a-138 e; again, clamps may be used to retain flanges 134 in position.This assembly is then turned so that is rests upon inner legs 144 andinner edges 135 a-135 e.

Next, remaining with FIGS. 3 and 9, one of upper tube segments 165 a isaligned with one of the set of flange holes 170 a-170 e, and insertedtherein. Once fully inserted, proximal end 166 a substantially alignswith proximal face 172 a of VBS flange 134 a, and distal end 167 asubstantially aligns with distal face 173 e of VBS flange 134 e. Thisprocess is repeated for the second of tube segments 165 a and flangeholes 170 a-170 e. Next, inward surfaces 141 b of beam segments 139 bare preferably tack welded, or clamped, at several points to side edges137 a, and then similarly for side edges 137 b-137 e, until inwardsurface 141 b is abutting and aligned to each of the opposing side edges137 a-137 e. Clamping or tack welding permits some flex, or “give” sothat should there be any need to adjust the alignment of the structure,this may more easily be done.

Next, both of upper tube segments 165 a are preferably removed from thestructure in order to permit more room for access by a welder, and onceall items are in alignment, inward surface 141 b of one of beam segments139 b is welded to side edge 137 a, by applying a bead along theinterface therebetween on first proximal face 172 a, then distal face173 a. This process is repeated for the second of beam segments 139 b,joining it to the second side edges 137 a. This process is then repeatedfor side edges 137 b-137 e, for both of beam segments 139 b. The orderin which the side edges are joined to beam segments 139 b may bealtered, for instance by joining all side edges to one beam segmentfirst, or by starting from VBS flange 134 e, or in some other order. Ifupper tube segments 165 a were removed from the structure, they may bereplaced now. Then flange 134 a is joined to one of upper tube segments165 a by laying a weld bead along the interface of flange hole edge 171a and surface 168 a at one or both of proximal and distal faces 172 a,173 a of flange 134 a. This process is repeated for each of flanges 134b-134 e, and then for the second of upper tube segments 165 a. Thesequence in which the flanges are welded to tube segments may be varied,such as by alternating tubes, and completing each flange beforecontinuing to the next.

Remaining with FIGS. 3 and 9, for lower boom segment 26 this process isrepeated with beam segments 139 a. One of beam segments 139 a is laid onthe flat outer surface, with inward surface 141 b and legs 144, 145facing upwardly, and flange 134 f is set therein. VBS flange 134 f, anend cap, is substantially aligned to proximal end 142 a, with inwardsurface 141 a abutting side edge 137 f and with inner and outer legs144, 145 congruently engaging channel cuts 138 f. VBS flanges 134 f-134i are placed similarly, as in upper boom segment 28. VBS flange 134 i,an end cap, is substantially aligned to distal end 143 a. Similarly, oneof lower tube segments 165 b is aligned with one of the set of flangeholes 170 f-170 i, and inserted therein. Once fully inserted, proximalend 166 b substantially aligns with proximal face 172 f of VBS flange134 f, and distal end 167 b aligns with distal face 173 i of VBS flange134 i. This process is repeated for the second of tube segments 165 aand flange holes 170 f-170 i. A similar welding process is then carriedout as in upper boom segment 28, preferably with tube segments 165 bhaving been removed during welding of flanges 134.

Turning to FIG. 9, upper boom segment 28 and lower boom segment 26 arejoined at their respective distal and proximal ends, 30 a, 29 b,preferably by hinge 31, which is preferably located between VBS flanges134 e, 134 f, adjacent to outer edges 136 e, 136 f. Hinge 31 permits arange of motion of lower boom segment 26 relative to upper boom segment28, preferably at least about 180 degrees about hinges 31's axis ofrotation 31 a. This range of motion is shown in FIG. 1D. Axis ofrotation 31 a preferably runs parallel to outer edges 136 e, 136 f.

Turning to FIGS. 1D and 6A, the lower boom section stowage systemcomprises hinge 31, cable 34, winch 35, sheaves 36 a, 36 b and latches37. Latches 37 have open and closed positions, and are also locatedadjacent distal and proximal ends, 30 a, 29 b, preferably on distal end143 b of beam segment 139 b and proximal end 142 a of beam segment 139a, on the sides of beam segments 139 a, 139 b. Latches 37 are heavyduty, preferably 8,000-pound, stainless steel locking clamps, suitablefor bolting to the sides of beam segments 139 a, 139 b. Latches 37 alsopreferably have locking pins, to prevent accidental opening of thelatch. A KNU-VISE brand PC-8000-SS clamp by Lapeer Manufacturing, LapeerMich., 48446 was found to be acceptable. In a closed position, latches37, in coordination with hinges 31, hold flange 134 f of lower boomsegment 26 in a close relationship with flange 134 e of upper boomsegment 28, and maintains a rigid connection therebetween. This providesthe down position of vertical boom section 22. In an open position,latches 37 permit inner edge 135 f of flange 134 f to move arcuately andaway downwardly from edge 135 e of flange 134 e, permitting lower boomsegment 26 to rotate about axis 31 a of hinges 31.

Referring to FIGS. 1D and 9, in one embodiment, hinges 31 are sets ofknife hinges, one set each mounted to each side of vertical boom section22, at the point at which flange 134 e and flange 134 f abut, andproximate to outer legs 145 of beam segments 139 a, 139 b. The pin inknife hinges 31 is aligned to create axis 31 a, which in thisembodiment, is about three inches outward of outer legs 145. Knifehinges offer the advantage that they are self-aligning, in axis 31 a,and offer a more precise and repeatable positioning of lower boomsegment 26 relative to emitter 112. In another embodiment, hinge 31 isat least one piano hinge, having axis 31 a, which is mounted to theouter faces of upper and lower boom segments 28, 26, at the point atwhich flange 134 e and flange 134 f abut.

Referring to FIG. 1C, stow cable 34, used in the stowage system, is usedto raise and fold back the lower boom section, and is preferably riggedin a double line pull configuration, in order to reduce winch powerrequirements. Stow cable 34 is directed by, and accomplishes stowage byacting at sheaves 36. Sheaves 36 are stainless steel, V-shaped, wirecable sheaves, of about three inch diameter. Lower sheave 36 a islocated near distal end 29 a of lower boom segment 26, and near outeredge 136 i of VBS flange 134 i, on the outer surface of the boomsegment, and is preferably set a small distance off that surface tofacilitate passage of cable 34 about sheave 36 a. First and second uppersheaves 36 b are located on distal face 200 of terminal flange 198, andare also set a small distance off that surface to facilitate passage ofcable 34. The second upper sheave 36 b is set below the first,approximately 24 inches. Cable 34 should be a braided steel cablesuitable for use on a winch, and be sufficiently long to reach fromproximal end 30 b sheave 36 a, back to proximal end 30 b, and then towinch 35 (in FIGS. 1D and 6A). In a preferred embodiment, its length isabout fifty feet long and its diameter about {fraction (3/16)} inch. Oneend of stow cable 34 is fixed to the outer surface of upper verticalboom segment 28, at a point slightly below the position of lower sheave36 a, when lower boom segment is in the stowed position. In the stowedposition, cable 34 passes downwardly, outward of boom segments 26 and28, and adjacent to outer panels 83, and approaches sheave 36 a from itsinterior side, and wraps around sheave 36 a, and is redirected upwardlyfrom the exterior side of sheave 36 b. Cable 34 then passes upwardly,outward of the above length, and approaches second upper sheave 36 bfrom its interior side, and passes to the outward side of first uppersheave 36 b. After being redirected toward horizontal boom section 20,and turning to FIGS. 8A and 8B, cable 34 enters instrument boom 10through cable chase 204 in distal face 200 of terminal flange 198.Referring to FIG. 6B, cable 34 then enters horizontal boom section 20 atdistal end 46 of inner tube 40, which is open at HBS flange 66 k, and,in FIG. 6D, leaves it at proximal end 44, at flange 66 a. Cable 34 thenpasses between upper and lower frames 207 a, 207 c of rear frame 207.Cable 34 then reaches winch 35, which is mounted to the interior ofmast-head 14, and in one embodiment above, and indirectly to, mast-headplate 97.

Referring to FIGS. 1C and 1D, with latch 37 in an open position, winch35 draws in cable 34, which applies an upward force upon distal end 29 aat sheave 36 a, causing end 29 a to swing upwardly and outwardly onhinges 31. As end 29 a swings out, cable 34 exerts an upward and inwardforce. Continuing, as end 29 a continues upward, outer panels 83 willreach a position approximately level with ground 125. As cable 34continues to be drawn in, end 29 a will approach outer panels 83 onupper boom segment 28, and hinges 31 will approach their 180 degreeextension. Finally, in the stowed position, hinges 31 are at about 180degree extension, outer edge 136 i of flange 134 i is near upper boomsegment 28, and the outer panels of 83 of boom segment 26 are aboutthree inches outward of those on boom segment 28, due to the location ofaxis 31 a. FIG. 2B depicts the fully stowed position. In the stowedposition, lower boom segment 26 and its longitudinal axis 25 a issubstantially collinear with upper boom segment 28 and its longitudinalaxis 27 a.

Turning now to FIGS. 8A, 8B and 18, horizontal boom section 20 andvertical boom section 22 are preferably joined by box joint 59 andgusset assembly 61. Box joint assembly 59 is preferably constructed asfollows. Ears 146 on upper beam segment 139 b extend across the C-shapeddistal ends 64 of horizontal beams 56. The inner surfaces of ears 146closely abut distal ends 64, which extend beyond end cap flange 66 k.Ears 146 and beams 56 are joined by welding; in one embodiment, C-shapeddistal ends 64 are welded about at the joint with ears 146 on upper leg58 b and the side of beams 56, and at the inner periphery of lower leg58 a. In a further embodiment, inner edge 135 a of end cap flange 134 ais welded to lower edge 72 k of end cap flange 66 k, but solely on theinside of instrument boom 10. In addition, proximal ends 142 b of beamsegments 139 b, save for ears 146, closely abut the lower surface oflower legs 58 a and are welded thereto, preferably along the outerperiphery of inner leg 144 of beam segment 139 b, and along the side ofbeam segment 139 b. The structure is preferably held tightly togetherduring the welding process, such as by using clamps and other supports,to prevent deformation of the joints due to heat expansion. The weldsmay be accomplished in various orders, however, joining ears 146 tobeams 56, one at a time, and then joining proximal end 142 b to beams 56was acceptable. It is important to maintain a 90-degree angle betweenhorizontal and vertical boom sections 20, 22, in order to obtainaccurate scanning results. Altering the order of welding to counteractresults of heat expansion may be necessary and may further depend uponambient environmental conditions. Exposed welds are preferablysubstantially flush with the outer surfaces of beams 56 and beam segment139 b to facilitate joining gusset assembly 61 to horizontal andvertical boom sections 20, 22.

Remaining with FIGS. 8A, 8B and 18, gusset assembly 61 preferablyincludes gusset plates 147, gusset channel beam 148 and bolts 206.Plates 147 are metal plates, preferably triangular pieces of T6 6061aluminum, ¼ inch thick, having one right angle and two sides of at leastabout 20 inches, and preferably about 22-26 inches, adjacent to theright angle. Gusset channel beams 148 are sections of 3″ C-channel beamabout ¼ inch thick, also preferably T6 6061 aluminum, cut to runadjacent to the edges of plates 147, opposite to the right angle. Thelong, outward face of beams 148 abuts the outer surfaces of beams 56 and139 b. Beams 148 are preferably about 30 to about 40 inches in length,preferably extending fully diagonally across beams 56 and beam segments139 b. Plates 147 are located with the right angle placed at theintersection of upper legs 58 b and ears 146, and the adjacent legsrunning downwardly and inwardly along the edges of outer legs 145 andupper legs 58 b. Plates 147 are preferably joined to beams 56 and beamsegment 139 b using structural bolts 206. An acceptable bolt patternincludes about nine along each adjacent side, about ten along theopposite side, and five further extending from side to side atintermediate points along each side. Beams 148 are also preferablyjoined using bolts 206, six bolts each joining the beams to beam 56 andbeam segment 139 b being acceptable.

Turning to FIGS. 8B and 9, preferably, a terminal flange 198 is locatedbetween ears 146 of upper beam segment 139 b. Terminal flange 198 is afurther flange, in line with HBS flanges 66 a-66 k, but not joined toinner tube 40 or outer tube segments 48 a-48 j. Flange 198 servesprimarily as a point of attachment for tension cable distal end points152, and to block off the open space between the distal ends of beams56. Turning to FIGS. 13A and 13B, in one embodiment, flange 198 is asingle plate; in another it is a composite plate, comprised of two toabout four thinner plates, welded together face-to-face (seen in FIG.6B). Flange 198 includes proximal and distal faces 199 and 200, side,top and bottom edges 201, 202 and 203, tension cable chases 205 and stowcable chase 204. Turning to FIGS. 6B and 8A, tension cable chases 205are aligned with cable chases 80 a-80 k in the HBS flanges 66, and, inFIG. 13A, have a diameter c9, while stow cable chase 204 is slot-shaped,and aligned with distal end 46 of inner tube 40. Flange 198 is cut tofit within the gap (see FIG. 9) created between VBS flange 134 a andears 146, and has width w9 along top and bottom edges 202, 203, heighth9 along side edges 201, and thickness t9 between faces 199, 200. In anembodiment using composite plate flange 198 (see FIG. 6B), inner plates,near proximal face 199, have a width w9 greater than those of outerplates, near distal face 200, in order that the longer plates overlapears 146, and the shorter plates fit between ears 146.

Turning to FIGS. 8A, 8B and 18, two braces 214 are preferably used tomake box joint 59 more rigid, and to reinforce terminal flange 198 wherecable 150 applies tension at attachment points 152. Each of braces 214include forward ends 217 and rear plates 216, and is generally“L”-shaped viewed from above, with the long side being forward end 217.The vertical portion of forward ends 217 abut distal face 70 k of endcap flange 66 k, and the bottom side abutting end cap flange 134 a, andis situated slightly inwardly of legs 58 a and 144. Rear plate 216extends outwardly from forward end 217, with its vertical portionabutting inward surface 60, and its bottom side notched to accommodaterear plate 216 abutting the inner surface of lower leg 58 of beam 56,and end cap flange 134 a. Rear plate 216 has 1½ inch holes therethroughto permit passage of the studs of cable 150, and is joined by welding toproximal face 199 of terminal flange assembly 198, to inward surface 60of beams 56, and to legs 58 a. Forward end 216 is welded to end caps 134a, 66 k.

Returning to FIGS. 13A and 13B, in one preferred embodiment h9 is about10 inches, w9 is about 15-16 inches, t9 is about one inch, stow cablechase 204 is about 1¼ inches by about 2½ inches, and c9 is about 1¼inches. In another preferred embodiment, a composite flange 198 includesfour plates, each having thickness t9 of about ¼ inch, and having widthsof 15-16 inches and about 20-22 inches. Flange 178 is preferably T6 6061aluminum. Referring to FIG. 8A, in one embodiment, it is joined bywelding side edges 201 to the inner edges of ears 146, and bottom edge203 to outer edge 136 of flange 134 a. Turning to FIG. 6B, in acomposite terminal flange 198, side edges 201 of narrower plates arewelded to the inner edges of ears 146, while wider plates overlap, andare welded to the inner face of ears 146, and bottom edge 203 is weldedto outer edge 136 of flange 134 a.

Referring to FIG. 1C, sensor packages 24 comprise a significant portionof the load borne by horizontal and vertical boom sections 20, 22, andtotal about 1800 pounds. This weight is roughly evenly split between thetwo sections, with about a {fraction (9/11)} split between horizontalboom section 20 and vertical boom section 22.

In an alternative embodiment, in horizontal boom section 20′, inner tube40 and outer tube segments 48 a-48 j and HBS flanges 66 a-66 k arereplaced by structures depicted in FIGS. 17A, 17B and 17C. Thisalternative structure can offer both advantages in weight reduction byutilizing thinner-walled tubes in the horizontal boom section and inconstruction time by utilizing a simpler construction method. Thisalternative horizontal boom section 20′ utilizes several componentssimilar to those in section 20, and these components having the same ornearly the same components and functions will be identified by use of aprime, thusly—′—. Referring to FIG. 17C, horizontal boom section 20′comprises a first support assembly, preferably treble tube assembly 230,longitudinal and transverse axes 21 a′, 21 b′, second support members,preferably beams 56′, and a number of trilobe flanges 225, arrayed in aspaced relationship to one another, similar to the relationship depictedin FIG. 6A for HBS flanges 66, and as in FIG. 17C. Boom section 20′ alsocomprises upper HBS panel 81′. In a preferred embodiment, there areeleven trilobe flanges 225 a-225 k. Referring to FIGS. 17A and 17B,flange 225 a comprises trilobe flange hole 226 a, flange hole edge 227a, proximal face 68 a′, distal face 70 a′, upper, lower and side edges72 a′, 73 a′ and 74 a′, channel cuts 75 a′ and cable chases 80 a′.Trilobe flange hole 226 a is shaped roughly in the form of three circlesof equal radius, arranged such that their centers form an equilateraltriangle having a point facing downwardly and the opposite edge parallelupper edge 72 a′. In another embodiment, the point of the equilateraltriangle could face upwardly or otherwise. The center of the equilateraltriangle is approximately centered in flange 225 a, preferably, slightlylower than center. The circles are joined at their points of tangency.All material is removed interior to the circles, as is that exteriormaterial radially inward from the three tangency points toward thecenter of the equilateral triangle. Trilobe flange hole edge 227 a isdefined by the convex portions of the three circles running from onetangency point to another, the three portions joined at the tangencypoints. Preferably, a small amount of material is removed radially atthe tangency points, away from the center of the triangle, to avoidcreation of very small, to narrow width flange pieces. Preferably, thismaterial is removed about ¼ inch from the point of tangency. Trilobeflange holes 226 a is sized to accept, preferably closely, treble tubeassembly 230. Trilobe flange 225 a is constructed of aluminum plate.Flange hole 226 a and cable chases 80 a′ can be removed by variousmachining processes for cutting thick metal pieces known to persons ofskill in the art, such as a plasma cutter, or a water jet cutter. Inthis embodiment, trilobe flange 225 a has height h4′, thickness t4′ andwidth w4′, and cable chases 80 a have diameter c4′. In a particularlypreferred embodiment, flange 225 a is constructed of 6061 T6 aluminum,h4′ is about 10 inches, t4′ is about one inch, w4′ is about 23 inches,c4′ is about two inches, and d4 is slightly greater than d1, about4{fraction (1/16)} inches. Trilobe flanges 225 b-225 k have similarfeatures labeled using those respective suffixes. Flange holes 226 a-226k should be aligned to an axis coincident to tube assembly axis 231. Ina particularly preferred embodiment, the spacing between the opposingdistal and proximal faces of adjacent flanges (e.g. a-b is betweendistal face 70 a′ and proximal face 68 b′) is as follows: a-b throughc-d, about 15 inches; d-e, about 9 inches; e-f through j-k, about 23inches. Trilobe flange 225 a will ordinarily be typical, save for thevarying position of cable chases 80 a′-80 k′, but need not be.

Turning to FIG. 17C, treble tube assembly 230 includes longitudinal axis231 and three tubes 232 a-232 c. In one embodiment, tubes 232 a, 232 bare lower tubes, having longitudinal axes 234 a, 234 b parallel to andsubstantially level with one another. Upper tube 232 c has longitudinalaxis 234 c parallel to axes 234 a, 234 c, but located between and abovethem. Other orientations are possible, such as one lower tube and twoupper tubes. Tubes 232 a, 232 b and 232 c each have surfaces 233 a-233c, proximal ends 236 a-236 c and distal ends 237 a-237 c. In a preferredembodiment, tubes 232 a-232 c are hollow, aluminum cylinders, havingcircular cross section and having length n11, outer diameter d11 andtube wall thickness t11. In a particular preferred embodiment, d11 isabout four inches, t11 is from about ⅜ to about ¼ inch, n11 is about 200inches and tubes 232 a-232 c are constructed of 6061 T6 aluminum. Aswith inner tube 40, a solid rod could be used, but a hollow tube isadvantageous. Lower tubes 232 a, 232 b are side by side, and havesurfaces 233 a, 233 b abutting one another at the tangency point.Directly above lies tube 232 c, having surface 233 c abutting surfaces233 a, 233 c at tangency points on their upper sides. All three tubes232 have their respective ends 236 and 237 substantially aligned to oneanother.

The alternative horizontal boom section 20′ is constructed similarly toupper boom segment 28, using the techniques described above. Thefollowing modifications and substitutions are preferably made to thatprocess. Trilobe flanges 225 a-225 k, tubes 232 a-232 c, beams 56′ andtheir constituents are substituted for VBS flanges 134 a-134 e, tubesegments 165 a, beam segments 139 b and their constituents,respectively. In addition, tubes 232 a-232 c need not be removed fromtrilobe flanges 225 a-225 k during the welding process, as they permitbetter access to the flanges. Further, after flanges 225 are joined totreble tube assembly 230, each of tubes 225 a, 225 b and 225 c arepreferably joined to one another by welding longitudinally along thetangency point between surfaces 233 a, 233 b and 233 c. Such welds arepreferably not continuous, but rather are short welds, spacedapproximately one foot apart. It may be necessary to invert thestructure to accomplish this step for the a-b interface. The sequence inwhich the flanges are welded to tubes may be varied, such as bybeginning at flange 225 k, or by welding the tubes together first.

I claim:
 1. A boom, having longitudinal and transverse dimensions,comprising: a first longitudinal member having an external surface; asecond longitudinal member oriented substantially parallel to said firstlongitudinal member; said second longitudinal member comprising aplurality of segments, each segment comprising ends; one or moresubstantially transverse flanges each having edges and opposing facesand defining at least one hole from one face to the other, wherein thefirst member extends through the hole; wherein said first member isinternal to said second member, and at least one end of each segment isjoined to the face of said one or more flanges, and the external surfaceis joined to said one or more flanges; and a plurality of thirdlongitudinal members, wherein said third members are joined to the edgesof the one or more flanges.
 2. A boom having, longitudinal andtransverse dimensions comprising: a first longitudinal member; a secondlongitudinal member oriented substantially parallel to said firstlongitudinal member; one or more substantially transverse flanges eachhaving edges and opposing faces and defining at least one hole from oneface to the other, wherein the first member extends through the hole; aplurality of third longitudinal members, wherein said third members arejoined to the edges of each of the one or more flanges; and said firstand second longitudinal members each further comprising an externalsurface; wherein said external surfaces are joined to said one or moreflanges.
 3. A boom having longitudinal and transverse dimensions,comprising: a first longitudinal member comprising a tube, wherein saidtube is continuous along substantially the length of the boom; a secondlongitudinal member oriented substantially parallel to said firstlongitudinal member; one or more substantially transverse flanges eachhaving edges and opposing faces and defining at least one hole from oneface to the other, wherein the first member extends through the hole;and a plurality of third longitudinal members, wherein said thirdmembers are joined to the edges of each of the one or more flanges. 4.The boom of claim 3, wherein said tube is circular in cross-section. 5.A boom having longitudinal and transverse dimensions, comprising: afirst longitudinal member; a second longitudinal member orientedsubstantially parallel to said first longitudinal member; said secondmember comprising a plurality of tubes surrounding said first member andsubstantially concentric with said first member; one or moresubstantially transverse flanges each having edges and opposing facesand defining at least one hole from one face to the other, wherein thefirst member extends through the hole; and a plurality of thirdlongitudinal members, wherein said third members are joined to the edgesof each of the one or more flanges.
 6. The boom of claim 5, said firstmember comprising a tube, and wherein said tube is continuous alongsubstantially the length of the boom.
 7. The boom of claim 5, whereineach end of the plurality of tubes is joined to one of said one or moreflanges and each of said one or more flanges has one or more sectionsjoined thereto.
 8. A boom having longitudinal and transverse dimensions,comprising: a first longitudinal member; a second longitudinal memberoriented substantially parallel to said first longitudinal member; oneor more substantially transverse flanges each having edges and opposingfaces and defining at least one hole from one face to the other, whereinthe first member extends through the hole; and a plurality of thirdlongitudinal members, wherein said third members are joined to the edgesof each of the one or more flanges; said third members comprising asubstantially planar beam having an inward surface, and one or more legsalong the beam's longitudinal length; wherein said one or more legsextends from the inward surface normal to the plane of the beam, andsaid inward surface is joined to said edges.
 9. The boom of claim 8,said flange edges defining a plurality of depressions correspondingcongruently to said one or more legs, wherein said depressionsfacilitate engagement of said beams and said flange edges.
 10. A boomhaving longitudinal and transverse dimensions, comprising: a firstlongitudinal member; a second longitudinal member oriented substantiallyparallel to said first longitudinal member; one or more substantiallytransverse flanges each having edges and opposing faces and defining atleast one hole from one face to the other, wherein the first memberextends through the hole; a plurality of third longitudinal members,wherein said third members are joined to the edges of each of the one ormore flanges; a proximal end, and; an end support; wherein the boom issupported at the proximal end by the end support.
 11. The boom of claim10, further comprising a distal end, wherein a large fraction of theload is applied substantially at said distal end, and the boom'slongitudinal dimension is in a substantially horizontal plane.
 12. Theboom of claim 10, further comprising a distal end and secondarystructure, wherein said secondary structure is downwardly extending andis supported by the distal end of the boom.
 13. A boom havinglongitudinal and transverse dimensions, comprising: a first longitudinalmember comprising a continuous tube; a second longitudinal memberoriented substantially parallel to said first longitudinal member; saidsecond member comprising a plurality of tube segments; one or moresubstantially transverse flanges each having edges and opposing facesand defining at least one hole from one face to the other, wherein thefirst member extends through the hole; and a plurality of thirdlongitudinal members, said third members comprising C-channel beams;wherein said third members are joined to the edges of each of the one ormore flanges, and wherein said tube segments are outward of andconcentric to the continuous tube, and at least one of said tubesegments is joined to each of the opposing faces of at least one of saidone or more flanges.
 14. A boom having longitudinal and transversedimensions, comprising: a first longitudinal member; a secondlongitudinal member oriented substantially parallel to said firstlongitudinal member; one or more substantially transverse flanges eachhaving edges and opposing faces and defining at least one hole from oneface to the other, wherein the first member extends through the hole; aplurality of third longitudinal members, wherein said third members arejoined to the edges of each of the one or more flanges; a fourthlongitudinal member oriented substantially parallel to said firstlongitudinal member; and said first, second and fourth longitudinalmembers each comprising a substantially cylindrical tube; wherein eachof said tubes are adjacent to two other of said tubes and each tubeextends through the hole in each of the one or more flanges.
 15. Theboom of claim 14, wherein the hole in each of the one or more flanges istrilobed in shape, said tubes are joined to said one or more flanges atsaid hole, and said tubes are continuous along substantially thelongitudinal dimension of the structure.
 16. A boom having longitudinaland transverse dimensions, comprising: a first longitudinal member; asecond longitudinal member oriented substantially parallel to said firstlongitudinal member; one or more substantially transverse flanges eachhaving edges and opposing faces and defining at least one hole from oneface to the other, wherein the first member extends through the hole; aplurality of third longitudinal members, wherein said third members arejoined to the edges of each of the one or more flanges; a distal end;and at least one tensioning cable, wherein said cable applies an upwardforce upon said distal end.
 17. The boom of claim 16, further comprisingproximal end and a counterweight section, wherein said counterweightsection extends substantially longitudinally from the proximal end, saidcable is substantially longitudinal, and applies an upward force on saidcounterweight section.
 18. The boom of claim 16, wherein said cableextends substantially longitudinally within the boom.
 19. A boom havinglongitudinal and transverse dimensions, comprising: a first longitudinalmember; a second longitudinal member oriented substantially parallel tosaid first longitudinal member; said second longitudinal membercomprising a plurality of segments, each segment comprising ends; one ormore substantially transverse flanges each having edges and opposingfaces and defining at least one hole from one face to the other, whereinthe first member extends through the hole; said one or more flanges eachhaving a groove defined in at least one of said faces thereof; aplurality of third longitudinal members, wherein said third members arejoined to the edges of each of the one or more flanges; wherein saidfirst member is internal to said second member, and at least one end ofeach segment is joined to a face of said one or more flanges, and theexternal surface is joined to said one or more flanges.
 20. The boom ofclaim 19, wherein said grooves are circular and concentric to the holein the one or more flanges, and the ends of the segments join the one ormore flanges at the grooves.
 21. A structure for supporting a load on achassis comprising: a boom, said boom comprising a vertical support; afirst boom section having longitudinal and transverse dimensions, saidfirst boom section comprising: proximal and distal ends; an innercylinder having an outer surface, wherein said inner cylinder iscircular in cross-section and continuous along substantially thelongitudinal extent of the first boom section; a plurality of outer tubesegments, each comprising two ends, wherein said tube segments aresubstantially concentrically external of said inner cylinder; aplurality of longitudinal beams each comprising a substantially planarinward surface, and one or more legs along the beam's longitudinalextent, wherein said one or more legs extend from the inward surfacesubstantially normal to the plane of the beam; and one or moresubstantially transverse flanges having opposing faces and edges, eachflange defining at least one hole from one face to the other face, anddefining a plurality of depressions corresponding congruently to saidone or more legs, wherein said depressions facilitate engagement of saidbeams and said flange edges; wherein said inner cylinder extends throughthe hole in the one or more flanges, at least one end of each outer tubesegment is joined to the face of said one or more flanges, the externalsurface is joined to said one or more flanges, and the inward surfacesof said longitudinal beams are joined to the edges of said one or moreflanges; and a second boom section, said second boom section comprisingproximal and distal ends, wherein said second boom section is downwardlyextending and is supported by the distal end of the first boom section;wherein said vertical section is mounted to the chassis and supports theproximal end of the first boom section.
 22. The structure of claim 21,said one or more flanges each defining a circular groove in one or morefaces thereof, and the ends of the outer tube segments are inserted intothe grooves.
 23. The structure of claim 21, wherein both ends of eachtube segment are joined to two flanges.
 24. The structure of claim 21,said vertical support comprising a mast assembly; wherein said firstboom section is rotatable relative to said mast assembly and said firstboom section's longitudinal dimension lies in a substantially horizontalplane.
 25. The structure of claim 21, wherein said first and second boomsections are comprised of type 6061 T6 aluminum.
 26. In a mobiletransport, having a longitudinal axis, a support structure forsupporting a load at a distance from the transport, the supportstructure comprising: a first support, having upper and lower ends; asecond support comprising: proximal and distal ends; a longitudinalsupport member comprising an external surface; a plurality oflongitudinal sections; a plurality of substantially transverse flanges,each flange defining at least one passage therethrough; and a pluralityof longitudinal beams; wherein said longitudinal support member isinternal to said longitudinal sections, the flanges are arrayed in aspaced relationship along said longitudinal support member and areseparated from each other by one of the longitudinal sections, thelongitudinal support member extends through the passage of each flange,and the external surface, said longitudinal sections, and saidlongitudinal beams are each joined to said flanges; wherein the upperend of said first support is joined to said second support.
 27. Thesupport structure of claim 26, said longitudinal sections comprising twoends each; and said flanges each comprising two outer edges and opposingsurfaces through which said passage is defined; wherein said each end ofsaid longitudinal sections is adjacent to, and joined to, one of thesurfaces of one of the flanges, and said beams are joined to said edgesof said flanges.
 28. The support structure of claim 26, said firstsupport comprising a mast, wherein said mast is oriented along asubstantially vertical axis, and translates along that axis, and thesecond support structure is translated therewith.
 29. The supportstructure of claim 28, said first support further comprising acounterweight structure, wherein said counterweight structure is joinedto said second support, and is opposed to said second support.
 30. Thesupport structure of claim 28, said first support further comprising amast-head structure, wherein said mast supports the mast-head structure,and the mast-head structure is joined to the second support.
 31. Thesupport structure of claim 28, wherein said second support is rotatablerelative to the mast.
 32. The support structure of claim 26, furthercomprising a third support, wherein said second support extends adistance of at least about sixteen feet from the longitudinal axis ofthe transport, and the distal end of said second support supports thethird support.
 33. The support structure of claim 26, said secondsupport further comprising at least one tensioning cable, wherein saidcable applies an upward force upon said distal end.
 34. The supportstructure of claim 33, said first support further comprising acounterweight section, wherein said cable is substantially longitudinal,and applies an upward force on said counterweight section.
 35. Thesupport structure of claim 33, wherein said cable extends substantiallylongitudinally within the second support.